THE 


W.  K.  BURTON,  C.E., 

Professor  of  Sanitary  Engineering  Imperial  University  of  Japan, 

Author  of  "Modern  Photography"  "Photographic 

Printing, ' '  Etc. , 


ANDREW   PRINGLE, 

President  of  the  Photographic  Convention  of  the  United  Kingdom, 
1889,  Fellow  of  the  Royal  Microscopical  Society,  Etc. 


NEW   YORK: 

THE   SCOVILL  &  ADAMS   COMPANY, 
423  BROOM.E  STREET. 


Copyright,  1889, 
THE  SCOVILL  &  ADAMS  COMPANY. 


TR 

[45 


PREFACE. 


OF  the  two  writers,  both  have  zealously  followed  photog- 
raphy as  something  more  than  a  mere  amusement,  for  a  con- 
siderable number  of  years.  One  of  the  writers  has  studied 
the  science  from  a  theoretical  and  experimental  point,  while 
the  other  writer's  attention  has  been  almost  entirely  directed 
to  the  production  of  practical  results  by  the  processes  known, 
and  by  each  process  as  it  has  been  given  to  the  world.  As 
joint  authors,  therefore,  we  trust  that  our  joint  work  may  be 
acceptable  to  the  photographic  public ;  not  as  replacing,  or 
superior  to,  other  works,  but  rather  as  filling  a  place  not  occu- 
pied by  any  other  work.  The  chief  claim  made  for  our  work 
is  that  every  word  we  have  written  in  it  refers  to  subjects  with 
which  we  are  personally  and  intimately  acquainted;  not  a 
direction  nor  a  formula  is  given  on  trust,  every  one  has  been 
successfully  used  by  one  or  other  of  us,  in  most  cases  we  have 
both  used  the  formulae  found  in  this  book. 

At  first  our  MSS.  extended  to  a  very  considerable  length, 
and  treated  photography  completely  as  theoretical,  practical, 
and  artistic ;  but  circumstances  caused  us  to  abridge  our  work, 
and  to  produce  a  book  less  complete,  and,  perhaps,  less  inter- 
esting, but,  as  we  hope,  more  generally  useful,  not  only  to  ama- 
teurs and  beginners,  but  also  to  those  who  desire  authentic  in- 
structions and  formula  for  every -day  work.  Such  instructions 
and  formulae,  tested  carefully  by  ourselves,  and  likely  to  be 
useful  to  our  readers,  it  has  been  our  ambition  to  give  the  pub- 
lic. Whether  or  not  our  aspirations  have  been  fulfilled,  each 
member  of  the  public  may  judge  for  himself,  by  application 
(suitably  accompanied)  to  the  publishers  of  our  little  book ! 

W.  K  B. 
A.  P. 

861635 


CONTENTS. 


PAGE 

PREFACE,  3 

CHAPTER  1. 
INTRODUCTORY  AND  HISTORICAL,  -      7 

CHAPTER  II. 
THE  THEORY  OF  PHOTOGRAPHY,         -  -          12 

CHAPTER  III. 
APPARATUS,  -    16 

CHAPTER  IV. 
THE  DARK-ROOM,          -  -          80 

CHAPTER  V. 
"NEGATIVE"  AND  "POSITIVE,"   -  -    34 

CHAPTER  VI. 
THE  WET  COLLODION  PROCESS,          -  -    >      36 

CHAPTER  VII. 
A  DRY  COLLODION  PROCESS,        -  -    46 

CHAPTER  VIII. 
GELATINE  EMULSION  PROCESSES,  PRELIMINARY,        -  -          50 

CHAPTER  IX. 
GELATINE-BROMIDE  EMULSION,      -  -     55 

CHAPTER  X. 

GELATINE-BROMIDE  EMULSION,  BY  THE  AMMONIO-NITRATE  PROCESS, 
AND  PRECIPITATION  BY  ALCOHOL.— CENTRIFUGAL  SEPARATION,         60 

CHAPTER  XI. 
COATING  PLATES  WITH  GELATINE-BROMIDE  EMULSION,  DRYING,  ETC.,     69 

CHAPTER  XII. 
THE  CAMERA  IN  THE  FIELD,    -  -          73 

CHAPTER  XIII. 
EXPOSURE  AND  DEVELOPMENT  GENERALLY  TREATED,   -  -  -    81 


6  CONTENTS. 

CHAPTER  XIV.  PAGE 

DEVELOPMENT  OF  GELATINE-BROMIDE  PLATES, 

CHAPTER  XV. 
GELATINE-BROMIDE  PI.ATKS— FIXING,  INTENSIFICATION,  REDUCTION, 

ETC.,  -  96 

CHAPTER  XVI. 
DEFECTS  IN  GELATINE-BROMIDE  NEGATIVES,    - 

CHAPTER  XVII. 
PAPER  NEGATIVES  AND  STRIPPING  FILMS,   -  -          104 

CHAPTER  XVIII. 
"COLOR  CORRECT"  OR  "ORTHOCHROMATIC"  PHOTOGRAPHY,  -    110 

CHAPTER  XIX. 

STEREOSCOPIC  PHOTOGRAPHY,  -          115 

CHAPTER  XX. 

PART   II. 

PRINTING  PROCESSES,  PRELIMINARY,      -  -    118 

CHAPTER  XXL 
PRINTING  ON  ALBUMENIZED  PAPER  WITH  SILVER  CHLORIDE.        -          121 

CHAPTER  XXII. 

PREPARATION  OF  NEGATIVES  FOR  PRINTING,  COMBINATION  PRINTING,    |S3 
VIGNETTING,    -  -    188 

CHAPTER  XXIII. 
PRINTING  ON  PLAIN  SALTED  PAPER,  -         133 

CHAPTER  XXIV. 
GELATINE-CHLORIDE  PAPER  FOR  PRINTING-OUT,  -    140 

CHAPTER  XXV. 
CONTACT  PRINTING  ON  GELATINE  BROMIDE  PAPER,  -  -          142 

CHAPTER  XXVI. 
RAPID  PRINTING  PAPER,  .     148 

CHAPTER  XXVII. 
PLANTINOTYPE,  OR  PRINTING  IN  PLATINUM,  -          150 

CHAPTER  XXVIII. 
THE  "CARBON  "  PROCESS,  OR  "PIGMENT  PRINTING. "  -    156 

CHAPTER  XXIX. 
POSITIVES  AND  NEGATIVES  BY  ENLARGEMENTS,       -  -         164 

CHAPTER  XXX. 
LANTERN-SLIDES,    -  ------    171 


RESIDUES, 


CHAPTER  XXXI. 


182 


The  Processes  of  Pure  Photography. 


CHAPTER  I. 
INTRODUCTORY   AND  HISTORICAL. 

PHOTOGRAPHY  is  one  of  the  greatest  facts  of  the  present 
day.  Its  influence  is  of  very  wide  scope,  because  it  is  not 
only  an  almost  infallible  means  of  recording  facts,  but  also  a 
simple  means  whereby  the  artistically  inclined  may,  to  a  cer- 
tain extent,  find  expression  for  their  fancy.  Photography  not 
only  affords  us  evidence  of  what  we,  and  nature,  appear,  but 
enables  us  to  depict,  within  limits,  what  we,  and  the  rest  of 
nature,  might  be.  Briefly,  photography  is  at  once  a  science  and 
an  art.  Without  a  certain  knowledge  of  the  science,  we  can- 
not produce  any  effect  at  all,  artistic  or  otherwise ;  but  we  may 
master  the  science,  stop  there,  and  still  have  in  our  hands  a 
most  potent  agent  for  depicting,  graphically,  facts.  Again,  if 
our  ultimate  object  be  to  use  photography  as  an  art,  we  must 
master  the  science,  first  of  all,  that  we  may  be  able  to  produce 
a  graphic  result,  and  next,  that  we  may  control  our  result,  so 
that  our  scientific  means  may  lend  themselves  to  our  artistic 
aspirations;  and  the  more  control  over,  and  facility  in,  our 
scientific  operations  we  have,  the  more  fully  shall  we  be  able 
to  give  our  minds  to  the  realization  of  our  artistic  conceptions. 

In  the  same  way,  if  our  ultimate  object  be  purely  scientific, 
if  our  sole  ambition  is  to  give  true  photographic  copies  of  what 


8  THE   PROCESSES   OF   PUKE   PHOTOGRAPHY. 

we  see,  especially  if  we  see  it  under  difficulties,  such  as  those  of 
great  magnification,  or  reduction  in  size,  we  must  still  master 
our  photographic  science,  so  that  the  combined  difficulties  of 
seeing  and  depicting  what  we  see  may  not  overpower  and 
conquer  us, 

In  this  book  we  do  not  propose  to  deal  with  art,  nor  with 
any  science  except  purely  photographic  science ;  and  our  aim 
is  to  lay  bare,  as  clearly  as  space  will  permit  us,  the  principles 
regulating,  and  the  practices  most  suitable  for,  successful 
photography.  We  are  prevented  by  circumstances  from  fully 
entering  into  the  theories,  or  touching  on  more  than  very  few 
of  the  practices  which  control  successful  photography,  but  it 
is  our  ambition  to  so  lay  down  the  practice  that  close  elucida- 
tion of  the  theories  will  not  be  essential  to  the  intelligent 
reader,  or,  at  least,  so  that  the  reader  may,  while  acquiring  the 
power  of  producing  photographs,  be  only  tickled,  and  not  driven 
to  study  the  theories. 

On  the  above  basis  it  is  clearly  unnecessary  for  us  to  give 
more  than  a  cursory  resume  of  the  chief  results  that  mark  the 
history  of  photography.  The  great  landmarks  are  those  fol- 
lowing. We  can  attach  no  date  to  the  first  observation  of 
light  action  on  silver  chloride,  but  to  do  so  we  should  have  to 
go  back  at  least  300  years.  That  different  parts  of  the  solar 
spectrum  affected  silver  chloride  in  different  ways  was  observed 
by  Kitter  and  Seebeck,  in  1801  and'  1810.  Wedgewood  and 
Davey  observed  more  energetic  light  action  on  the  silver  salt 
on  a  basis  of  white  leather  than  on  paper.  This  contained  the 
germ  of  development  processes  acting  by  reduction  of  the  sil- 
ver salt,  the  tannin  of  the  leather  playing  the  important  part. 

Camera  photography  may  be  attributed  to  Joseph  Nicephore 
de  Niepce,  who  gave  the  first  authentic  account  of  it.  He 
used  bitumen  spread  on  a  metal  plate.  Bitumen,  on  exposure 
to  light,  loses  its  pristine  solubility  in  certain  oils.  With  de 
Nu>pce,  Daguerre,  a  miniature  portrait  painter,  in  1829,  en- 
tered into  partnership  ;  in  1839  the  Daguerreotype  process  was 
announced.  Between  these  dates  Kiepce  had  died,  and  what- 
ever share  of  the  credit  was  due  to  him  Daguerre  claimed  the 
whole  of  it,  and  attached  his  name  to  the  process.  Then  fol- 


THE    PROCESSES    OF    PURE    PHOTOGRAPHY.  9 

lowed  the  addition  to  the  silver  iodide  of  Niepce,  of  silver 
bromide,  by  Goddard,  in  1810  ;  also,  in  1840,  Sir  J.  Herschell 
added  an  important  step  to  the  progress,  discovering  the  solu- 
bility of  silver  salts  in  sodic  hyposulphite,  so  that  a  method 
was  no  longer  wanting  to  fix  the  image.  This  sodic  salt  is  an 
important  item  in  the  photographic  laboratory  of  the  present 
day. 

In  1839 — that  eventful  year  for  photography — Fox  Talbot 
published  his  first  process,  wherein  he  coated  paper  with  sodic 
chloride,  and  thereafter  brushed  over  it  silver  nitrate,  thereby 
forming  silver  chloride  in  presence  of  excess  of  silver  nitrate, 
the  basis,  with  the  addition  of  albumen,  also  suggested  by 
Talbot,  of  our  "  silver  printing  ".process  of  to-day 

Talbot  again  comes  to  the  front  with  an  enormous  stride  in 
his  negative  process,  whereby,  in  place  of  one  positive  picture 
being  the  ultimatum  of  a  whole  set  of  operations,  we  produce 
by  one  set  of  operations  a  negative,  forming  a  matrix  for  a 
theoretically  unlimited  number  of  positive  pictures.  (See 
chapter  on  Positive  and  Negative,  p.  34).  This  process, 
which  Talbot  called  "  calotype,"  was  a  development  process, 
the  reagents  being  silver  nitrate  and  gallic  acid,  the  latter  due 
to  the  Rev.  J.  B.  Eeade. 

About  1850,  Le  Gray  seems  to  have  suggested  the  use  of 
collodion  as  a  "  vehicle  "  for  the  sensitive  silver  salts  ;  Scott 
Archer  certainly  published  the  first  collodion  process.  It  is 
worthy  of  note,  however,  that  the  lately  deceased  Mr.  J.  G. 
Tunny,  of  Edinburgh,  has  stated  in  our  hearing,  that  Le  Gray 
furnished  him  with  a  good  practical  collodion  process  before 
Archer's  was  published  ;  and,  further,  that  he  (Mr.  Tunny) 
used  Le  Gray's  process  in  conjunction  with  the  "iron  de- 
veloper." 

For  many  years,  and  with  great  reason,  the  wet-collodion 
process  reigned  supreme ;  but,  grand  as  its  qualities  were,  it 
had  the  drawback  that  the  plates  had  to  be  used  wet,  and  a 
great  load  of  paraphernalia  had  to  be  carried  -afield  for  the 
work.  The  advent  of  dry-collodion  processes  was  felt,  as  a 
matter  of  convenience  at  least,  to  be  a  marked  advance.  The 
free  silver  nitrate  of  the  wet  process  was  replaced  by  other 


]0  Till.    l'Un(  I-SKS   OF    PUKE   PHOTOGRAPHY. 

iodine  absorbents  of  organic  nature,  and  photographers  "  ran 
riot "  among  such  substances  as  beer,  tea,  coffee,  tannin,  beef- 
tea,  tobacco — and  who  knows  what  besides  ! 
j  The  discovery,  in  1862,  of  the  alkaline  developer  gave  a 
great  "  fillip  "  to  dry  processes,  for  by  it  not  only  the  free  sil- 
ver nitrate  on  the  film  is  reduced,  but  also  the  silver  haloids  in 
the  film. 

The  bath  was  dispensed  with,  at  last,  in  favor  of  emulsion 
processes,  the  joint  invention  of  Messrs.  B.  J.  Sayce  and  W. 
B.  Bolton,  both  of  whom  are  to  be  credited  with  the  advance. 
Finally,  gelatine  replaced  collodion,  the  first  published  gela- 
tine emulsion  process  being  that  of  Dr.  R.  L.  Maddox,  in 
1871.  In  1874,  Mr.  R.  Kennett  made  gelatine  pellicle,  and,  in 
1878,  gelatine  began  to  leave  all  other  ".vehicles"  behind  it. 
In  this  year,  1878,  in  March,  Mr.  Charles  Bennett  published 
liis  process,  whereby  he  produced  gelatino-bromide  emulsion  of 
a  sensitiveness  that  utterly  overshadowed  all  previous  prepara- 
tions ;  this  he  achieved  by  prolonged  digestion  of  the  emulsion 
at  medium  temperature.  Mr.  Bolton  is  again  heard  of  in  his 
'  suggestion  to  gain  sensitiveness  by  short  boiling  in  presence  of 
a  minimum  of  gelatine  in  place  of  long  digestion  with  the  full 
bulk  of  gelatine.  The  only  really  important  modification 
since  that  was  the  ammonio- nitrate  process,  of  which  full  de- 
tails will  be  found  in  our  chapter  dealing  with  the  subject. 

In  development,  since  the  "  alkaline  developer "  was  pub- 
lished, we  have  to  record  no  striking  variation,  save  the  fer- 
rous oxalate  developer  of  Messrs.  Carey  Lea  and  W.  Willis. 
Mr.  Lea's  process  was  first  published,  but  we  are  able  to  state 
that  Mr.  Willis'  memorandum  of  the  process  was  in  the  hands 
of  the  editor  of  a  periodical  three  months  before  Mr.  Lea's 
process  was  published,  accident  only  depriving  Mr.  Willis  of 
the  credit. 

The  advances  in  printing  processes  have  been  of  no  less  im- 
portance than  those  in  negative  processes.  For  a  long  time 
the  production  of  prints  more  stable  than  those  formed  from 
silver  chloride  on  paper  was  a  problem,  but  the  discovery  by 
Mungo  Ponton,  in  1838,  of  the  sensitiveness  to  light  of  potas- 
sic  bichromate  in  presence  of  certain  organic  substances,  led 


THE    PROCESSES    OF    PURE    PHOTOGRAPHY.  11 

up  after  a  course  of  experiments  by  Becquerel,  Poitevin, 
Pouncey,  and  others,  to  the  publication,  by  Swan,  of  the  "car- 
bon "  or  "  pigment "  printing  process,  certainly  the  first  that 
could  go  under  the  name  of  "  permanent." 

Out  of  certain  other  qualities  of  chromates,  in  presence  of 
organic  matter,  arose  a  long  series  of  photo-mechanical  pro- 
cesses with  which  we  cannot  here  deal. 

The  platinotype  process,  treated  later  by  us,  is  due  to  Mr. 
W.  Willis. 

The  latest  advances  in  photography  are  connected  with 
"  orthochromatics  "  or  color  correct  photography,  and  in  this 
field  the  labors  of  Vogel,  Ives,  Eder,  Schumann,  and  Botham- 
ley  are  conspicuous. 

To  those  interested  in  the  historical  development  of  photog- 
raphy, we  recommend  the  "  History  of  Photography,"  by  "W. 
J.  Harrison. 


CHAPTER  II. 
THE  THEORIES  OF  PHOTOGRAPHY. 

LIGHT  is  supposed  to  consist  of,  or  to  be  produced  by,  waves 
of  a  substance  known  as  ether,  all-pervading  and  imponder- 
able. Light  is  merely  the  name  by  which  we  call  the  sensa- 
tion produced  upon  our  senses  by  these  ether  waves. 

Matter  is  supposed  to  consist  of  atoms,  particles  so  infmites- 
imally  small  as  to  be  incapable  of  division  and  in  constant 
motion  among  each  other.  "  Molecule  "  is  the  name  we  give 
to  an  aggregation  of  two  or  more  atoms  of  different  kinds  in 
combination. 

The  waves  constituting  light  are  not  all  equal  in  length  from 
crest  to  crest,  nor  do  they  travel  from  their  source  at  equal 
paces.  Some  light  waves  are  very  much  shorter  than  others, 
and,  moreover,  when  in  their  course  they  pass  from  a  medium 
of  one  density  into  a  medium  of  another  density,  some  waves 
or  "rays"  are  turned  out  of  their  course  ("refracted")  more 
than  others.  The  rays  formed  by  short  waves  are  turned  out 
of  then*  course  more  than  the  rays  formed  by  longer  waves. 
A  ray  of  white  light  is  composed  of  a  vast  number  of  waves 
of  different  lengths  and  different  "  refrangibilities,"  and,  more- 
over, at  each  extremity  of  the  scale  of  visible  wave-lengths  are 
rays  which  our  eye  cannot  appreciate,  just  as  in  sound  there 
are  waves  so  frequent  and  others  so  distant  from  each  other 
that  our  ear  fails  to  record  them  to  our  brain. 

The  visible  light  rays  which  are  shortest  from  crest  to  crest, 
and  which  are  the  most  "refracted"  on  changing  the  medium 
through  which  they  travel,  convey  to  our  mind  the  sensations 
of  what  we  call  blue  or  violet  colors.  Still  shorter  and  still 
more  refrangible  are  many  rays  invisible  to  us.  These  short, 


THE  PROCESSES  OF  PUKE  PHOTOGRAPHY.          13 

highly  refrangible,  visible  rays,  and  the  still  shorter  and  more 
refrangible  invisible  rays  are  remarkable  for  the  energy  with 
which  they  exert  chemical  action,  and  to  the  chemical  action 
exerted  by  these  rays  specially  we  owe  the  power  of  producing 
a  photographic  image.  The  usually  accepted  theory  is  that 
the  wave  length  of  these  chemical  rays  is  of  such  a  "measure" 
as  to  produce  vibration  synchronous  with  the  vibrations  already 
mentioned  as  taking  place  among  atoms,  and  so  either  causing 
entire  severance  between  the  atoms  forming  a  molecule,  or  else 
placing  these  atoms  in  such  a  condition  that  the  severance  is 
ready  to  take  place  when  suitable  steps  are  taken  or  conditions 
observed  to  complete  the  inchoate  process  of  separation.  In 
photography  with  silver  salts  the  molecule  consists  of  an  atom 
of  silver  and  an  atom  or  atoms  of  some  other  substance,  photo- 
graphic action  consisting  in  this  case  of  a  severance  between 
the  silver  atom  and  the  other  atom. 

If  all  the  rays  composing  visible  light  exerted  anything  like 
an  equal  amount  of  chemical  activity,  it  is  evident  that  photo- 
graphic action  might  take  place  and  yet  be  totally  useless  to  us, 
because  uncontrollable  by  us ;  for  in  that  case  we  should  be 
unable  to  see  any  of  our  processes.  But  it  so  happens  that 
while  we  have  some  of  the  rays  composing  white  light  exert- 
ing strong  chemical  action,  we  have  other  rays  of  much  greater 
wave-length  and  much  less  refrangibility  marked  by  much  in- 
ferior chemical  energy,  though  their  wave-lengths  are  still 
great  enough  for  our  eye  to  appreciate.  These  rays  which 
produce  on  our  mind,  tutored  by  our  eyes,  the  sensations  of 
orange  and  red  colors  are  called  "  heat  rays,"  and  beyond  the 
scale  of  visible  heat  rays  there  are  other  rays  even  longer  and 
even  less  refrangible,  and  possessing  even  less  chemical  energy 
than  the  visible  red  rays.  So  that  while  we  can  use  the 
"  chemical  rays "  of  light  to  obtain  photographic  action,  we 
can  use  the  "  heat  rays  "  to  enable  us  to  see  sufficiently  well 
to  manipulate  our  photographic  materials  while  we  prepare 
our  "  sensitive  "  substances,  and  while  we  complete  the  pro- 
cesses started  by  the  chemical  agency  of  light,  referred  to  by 
us  as  "  inchoate,"  but  ready  to  be  completed  under  certain 
conditions. 


14  THE   PROCESSES   OF   PURE   PHOTOGRAPHY. 

In  short,  by  a  non-chemical  or  "non-actinic"  light,  we  pre- 
pare our  sensitive  material ;  to  chemical  action  of  light  we  ex- 
pose it,  and  by  non-actinic  light  we  "develop"  the  action 
started  by  the  light ;  a  "sensitive  "  material  being  one  capable 
of  being  acted  upon  by  light. 

There  are  other  rays  forming  components  of  white  light  in- 
termediate between  the  heat  rays  and  chemical  rays,  in  points 
of  wave  length  and  refrangibility.  These  intermediate  rays 
have  a  speciality  of  their  own,  viz.,  visual  brightness,  and  we  call 
them  "yellow"  or  "green."  The  yellow  is  not  so  much  en- 
dowed with  heat  characteristics  as  the  red  rays,  nor  is  the 
green  so  remarkable  for  chemical  activity  as  the  violet  rays ; 
but  all  the  component  parts  of  a  ray  of  white  light  have  a  cer- 
tain amount  of  chemical  power,  and  a  certain  amount  of  heat- 
ing power,  just  as  all  the  visible  component  rays  of  white  light 
have  a  certain  amount  of  visual  brightness. 

If  an  opaque  object  appears  to  us  "  red,"  it  appears  so  in 
virtue  of  its  absorbing  the  other  rays  and  reflecting  to  our  eyes 
red  alone.  If  a  sheet  of  glass  were  stained  really  and  purely 
red,  no  visible  rays  would  pass  through  it  except  red.  An 
opaque  object  "reflects,"  a  transparent  object  "transmits," 
light ;  but,  so  far  as  color  is  concerned,  the  theory  holds  good 
for  reflection  as  for  transmission.  A  beam  of  white  light 
caused  to  change  its  course  by  being  passed  out  of  one  medium 
through  another  of  different  density  in  a  certain  simple  man- 
ner, may  be  analyzed  or  broken  up  into  its  component  rays,  so 
that  these  rays  can  be  distinguished  ocularly  from  each  other 
from  their  different  colors  and  by  the  different  directions  in 
which  they  travel  after  "  refraction,"  and  an  instrument  made 
for  the  purpose  of  facilitating  the  observation  of  these  differ- 
entiations is  called  a  spectroscope,  the  analyzed  or  separated 
and  colored  band  of  rays  being  called  a  "  spectrum." 

The  science  of  optics  depends,  equally  with  the  science  of 
photographic  chemistry,  on  these  qualities  of  light,  and  while 
the  refraction  per  se  is  the  action  most  useful  in  optics,  the 
coloring  dependent  on  the  "  bending  "  is  a  factor  that  requires 
to  be  carefully  minimized  or  totally  counteracted. 

The  chief  processes  of  photography  depend  on  what  is  called 


THE   PROCESSES   OF   PURE    PHOTOGRAPHY.  15 

"reduction,"  We  start  with  a  compound  of  (say)  silver  and 
something  else.  Actinic  light  either  "  reduces,"  or  prepares 
for  "reduction,"  our  compound,  and  the  "reduction"  consists 
in  removing  the  something  else,  and  leaving  the  silver  alone  to 
form  the  visible  photographic  image. 

The  optics  of  photography  are  directed  chiefly  to  regulating 
the  size  of  our  image,  light  unaided  is  quite  able  to  effect  all 
our  purposes,  but  without  the  aid  of  optical  appliances  light 
would  be  for  us  an  unmanageable  and  unprofitable  servant. 

We  do  not  expect,  and  still  less  wish,  this  summary  to  be 
taken  as  touching  more  than  the  extreme  outskirts  of  the  sub- 
ject of  photographic  theory.  We  believe  that  a  thorough 
mastery  of  the  whole  theory  is  almost  essential  to  a  thorough 
mastery  over  the  practice,  but  our  limits  absolutely  preclude 
other  explanation. 

Certain  processes  are  not  even  touched  by  the  above  remarks ; 
on  encountering  these  processes  in  their  turn,  we  shall  say  a 
word  or  two  on  the  special  theories  regulating  them. 


CHAPTER  III. 
APPARATUS. 

THE  apparatus  required  for  the  production  of  a  photograph, 
by  the  usual  processes,  may  be  summed  up  under  two  heads : 
1st.  Apparatus  for  producing  a  negative,  or  a  direct  positive. 
2d.  Apparatus  for  producing  prints  from  a  negative. 

The  apparatus  required  essentially  for  the  production  of  a 
negative  are,  a  camera,  a  lens,  and  an  apartment,  or  box,  illu- 
minated by  a  non-actinic  light.  (A  lens  is  not  absolutely  neces- 
sary, but  is  almost  always  used).  For  convenience  we  require  a 
support  for  the  camera,  and  vessels  of  suitable  size  and  shape 
for  chemical  operations. 

Cameras  are  merely  light-tight  boxes  for  preventing  light, 
other  than  that  passing  through  the  lens,  from  reaching  the 
sensitive  plate,  and  cameras  further  afford  a  means  of  varying 
the  distance  between  the  lens  and  the  sensitive  surface,  so  that 
the  plate  may  be  placed  at  one  focus  of  the  lens.  As  ocular 
examination  is  required  to  enable  us  accurately  to  place  the 
plate  in  that  focus,  the  camera  is  provided  with  a  piece  of  ground- 
glass  representing  the  sensitive  plate  in  position,  while  the  plate 
itself  is  securely  carried  in  a  light-tight  receptacle,  known  as 
a  "dark-slide,"  or  "carrier,"  until  the  light  is  to  act  upon  it 
in  the  camera,  at  which  juncture  a  shutter  is  removed  from  the 
slide  or  carrier  in  situ  in  the  camera,  so  that  the  light  irom 
the  lens  reaches  the  plate,  while  no  other  light  can  reach  it. 
Evidently  the  sensitive  plate,  when  undergoing  light-action, 
must  in  position  coincide  accurately  with  the  position  occupied 
by  the  ground-glass,  while  we  were  placing  the  ground-glass  in 
the  focus  of  the  lens.  This  coincidence  of  position  between 
ground-glass  and  sensitive  plate  is  known  as  "register." 


THE    PROCESSES    OF    PURE    PHOTOGRAPHY.  17 

As  a  matter  of  convenience  and  efficiency,  cameras  are  made 
in  two  types,  a  camera  for  outdoor  work,  and  a  camera  for 
studio  or  indoor  operations.  The  studio  camera,  not  requiring 
to  be  carried  about,  should  be  of  strong  material,  and  should 
have  every  mechanical  convenience  without  respect  to  weight. 
The  "  outdoor,"  "  landscape  "  or  "  tourist's  "  camera  should 
have  every  mechanical  motion,  and  be  made  of  the  strongest 
material  consistent  with  portability. 

Certain  conveniences  should  be  found  in  every  camera,  irre- 
spective of  weight,  and  certain  qualities  are  essential  to  every 
camera,  irrespective  of  all  other  considerations.  A  sufficient 
amount  of  stretch,  sufficient  strength,  and  complete  rigidity 
are  essentials  to  every  camera.  In  studio  cameras  these  quali- 
ties are  usually  present ;  in  tourist  cameras  they  are  frequently 
neglected  in  the  mania  for  lightness. 

A  camera,  for  perfect  efficiency,  should  have  a  front  so 
made  that  the  lens,  the  flange  of  which  is  attached  to  the  front, 
may  be  moved  up  and  down,  at  least,  and  across,  if  possible, 
parallel  to  the  sensitive  surface.  It  is  frequently  convenient, 
for  certain  reasons,  to  be  able  to  put  the  sensitive  surface  out 
of  perpendicularity  to  the  axis  of  the  lens ;  and  it  is  frequently 
convenient,  while  tipping  the  lens  upwards,  to  preserve  the 
parallelism  of  the  sensitive  surface  with  the  plane  of  sight,  or 
with  upright  objects  in  the  view.  These  desirable  qualities 
are  obtained  by  what  is  known  as  a  "  swingback." 

Time  and  temper  are  sometimes  lost  when,  on  an  oblong 
plate,  the  view  has  to  be  taken  with  the  plate  in  the  vertical 
position  instead  of  the  more  usual  horizontal.  If  the  camera 
be  not  unscrewed  from  its  bearings  on  the  stand  and  placed 
bodily  in  the  desired  position,  a  "  reversing  back  "  is  required, 
and  it  is  certainly  a  great  convenience.  The  camera-body  has 
to  be  made  square  for  a  reversing  back  to  be  permissible,  but 
the  extra  weight  and  expense  entailed  are  usually  made  up  for 
by  the  extra  convenience. 

To  save  weight,  the  greater  portion  of  camera-body  is 
usually  made  of  leather,  in  the  form  of  bellows ;  and  to  save 
bulk,  the  bellows  are  often  made  to  taper  more  or  less  towards 
the  front.  This  taper  is  convenient,  but  must  not  be  too  sud- 


18          THE  PEOCES8ES  OF  PURE  PHOTOGRAPHY. 

den  or  carried  to  too  small  a  point,  otherwise  the  bellows  may 
interfere  with  the  image. 

In  some  tourist  cameras  the  stretching  operation  is  effected 
upon  the  front,  in  others  upon  the  back  of  the  camera.  Each 
system  has  its  advantages,  and  each  its  disadvantages.  If  the 
front  part  of  the  base-board  projects  too  far  in  front  of  the 
lens,  there  is,  at  certain  times,  a  danger  of  the  projecting  front 
trespassing  on  the  field  of  the  lens.  We  figure  a  camera  of 


FIG.  1. 

each  of  the  types  in  general  demand,  No.  1  being  a  tourist 
camera,  No.  2  a  studio  camera.  It  is  not  within  our  province 
minutely  to  describe  any  special  camera ;  we  have  suggested 
what  we  consider  the  essentials  of  a  good  camera.  The  pur- 
chaser must  rely  upon  the  honesty  of  the  parties  with  whom 
he  deals.  Our  remarks  are  only  intended  to  prime  the  tyro, 
so  that  when  he  goes  to  make  a  purchase  he  may  have  at  least 
a  faint  idea  of  what  he  ought  to  ask  for. 

A  regular  studio  camera,  as  Fig.  2,  will  probably  be  suitable 
only  'to  a  professional  portraitist,  but  as  there  are  many  ama- 
teurs who  lay  themselves  out  for  portraiture,  and  as  to  prevent 
fatigue  on  the  part  of  either  and  confusion  on  the  part  of 
operator,  it  is  well  to  have  every  convenience.  We  have  shown 
the  general  appearance  of  a  studio  camera  that  will  fulfill 
every  condition  of  perfection. 

Not  the  least  important  part  of  the  camera  is  the  "dark 
slide"  or  "carrier"  already  mentioned.  As  it  is  the  recep- 
tacle wherein  the  sensitive  plate  is  carried,  and  as  it  comes  into 
play  at  a  time  when  the  operator  needs  all  his  faculties  about 
him,  the  dark  slide  must  not  only  be  thoroughly  strong  and  ab- 


THE   PROCESSES    OF   PURE    PHOTOGRAPHY.  19 

solutely  liglit-tiglit,  but  sliould  be  of  such  neat  workmanship 
as  to  work  certainly  and  "  sweetly  "  under  all  circumstances. 


FIG.  2. 

For  dry-plates,  now  almost  universally  used,  the  slide  is  usually 
made  '•  double,"  carrying  two  plates  back  .to  back,  with  an 
opaque  partition  between  them.  The  double  slide,  as  a  rule, 
opens  at  one  end,  after  the  manner  of  a  long  pocket-book. 
The  partition  must  separate  the  plates  over  all  their  surface, 
and  may  conveniently  be  hinged  on  the  slide. 

When  it  is  desired  to  use  in  the  dark  slide  a  plate  of  a  size 
less  than  the  full  size  of  the  slide,  we  use  what  is  known  in 
England  as  a  "  carrier,"  in  America  as  a  "  kit,"  merely  a  frame 
fitting  internally  the  small  plate,  externally  the  dark  slide 
rebate. 

In  America  the  "  shutter "  of  the  dark  slide — the  part  re- 
moved from  the  front  of  the  plate  during  exposure — is  so 
made  as  to  pull  right  out  of  the  slide,  having  a  "cut-off"  to 
prevent  light  entering  as  the  shutter  comes  out  and  is  re- 
placed. In  England  the  shutter  has  usually  a  "  stop,"  which 
prevents  it  from  coming  right  out,  and  hinges  which  allow  it 
to  be  folded  out  of  the  way  and  out  of  the  wind  during  ex- 
posure. We  do  not  venture  to  decide  between  these  two  sys- 
tems ;  each  has  its  merits. 


20  THE   PROCESSES  OF  PURE   PHOTOGRAPH Y. 

"Koller  slides"  or  "roll-holders"  for  carrying  paper  films 
shall  be  noticed  later. 

The  considerations  that  regulate  the  choice  of  supports  or 
stands  for  the  camera  are  pretty  much  the  same  as  those  regu- 


FIG.  3. 

lating  the  choice  of  the  camera  itself.     The  studio  stand  must 
have  every  motion,  irrespective  of  weight,  and  two  good  sam- 


FIG. 


pies  are  shown  at  Figs.  3  and  3a.     A  stand  for  outdoor  pur- 


THE   PROCESSES   OF   PUKE   PHOTOGRAPHY. 


21 


poses  must  be  as  rigid  as  possible,  consistent  with  portability ; 
should  have  sliding  legs  to  meet  contingencies  of  very  uneven 
ground,  but  should,  withal,  pack  into  as  small  bulk  as  possible. 
The  point  upon  which  rigidity  chiefly  depends  is  the  breadth 
and  force  of  grip  with  which  the  tripod  head  is  grasped  by 
the  tops  of  the  legs.  Fig.  4  shows  a  good  tripod  stand. 


FIG.  4. 

Photographic  lenses  are  of  a  few  different  types,  and  made 
of  many  different  focal  lengths.  The  focal  length  of  a  lens  is 
really  the  paramount  consideration,  provided,  of  course,  the 
manufacture  is  good.  Each  type  of  lens  is  made  with  a  view 
to  meet  certain  special  requirements,  to  a  special  degree,  and  a 
good  lens  for  any  special  purpose  is  really  a  pure  compromise 
between  a  number  of  qualities,  special  attention  being  given  to 
the  special  quality  required  for  the  special  purpose.  Thus  the 
portrait  lens,  the  triumph  of  photographic  optical  compromises,  is 
so  made  as,  with  the  least  possible  sacrifice  of  other  qualities,  to 
give  the  greatest  possible  rapidity  of  action.  The  portrait  lens 
was  the  outcome  of  the  struggle  for  rapidity  at  any  price,  in 
the  days  of  slow  plates ;  it  is  now  gradually  falling  into  disuse, 
and  its  place  is  being  taken  by  the  rectilinear,  or  symmetrical 


22  THE   PROCESSES   OF   PURE   PHOTOGRAPHY. 

lens.  The  rectilinear  lens  is  formed  of  two  combinations, 
sometimes  alike,  sometimes  dissimilar.  Its  uses  are  at  least 
two-fold,  it  secures  rectilinearity  of  lines  in  the  camera  image, 
and  it  enables  us,  under  certain  conditions,  to  work  rapidly ; 
hence  we  have  the  term  " rapid  rectilinear,"  or  '-rapid  sym- 
metrical." We  have  other  "  symmetrical "  lenses,  which,  by 
reason  of  their  special  uses,  cannot  be  used  at  all  times  for 
rapid  work.  The  term  "wide-angle"  is  so  frequently  used, 
without  comprehension  of  its  true  signification,  that  we  explain. 
The  "covering  power"  of  a  lens  depends  mainly  upon  its 
focal  length,  and  if  we  use  a  lens  to  cover  a  plate  large  in  pro- 
portion to  the  focal  length  of  the  lens,  we  are  using  that  lens 
at  a  "  wide-angle " ;  so  it  has  come  about  that  lenses  made 
with  a  view  to  cover  a  plate  large  in  proportion  to  their  focal 
length  are  called  "  wide-angle  lenses."  A  lens  is  used  as  a  nar- 
row, or  wide,  or  medium  angle  lens  according  to  the  size  of  the 
plate  upon  which  it  is  used,  in  proportion  to  its  focal  length. 
A  complete  treatise  on  these  subjects  would  require  a  vast 
amount  of  space,  more  than  we  can  give  the  subject  here. 

The  so-called  "  single  "  lens  has  certain  qualities  which  place 
it,  in  our  estimation,  higher  than  any  other  kind  of  lens.  The 
number  of  reflections  inside  the  lens  is  reduced  to  a  minimum, 
and  the  result  is  a  quality,  especially  in  the  shadows,  not  given 
by  doublet  or  triplet  lenses.  Until  lately  the  single  lens  had 
to  be  so  "  stopped  down  "  as  to  make  its  action  very  slow,  but 
this  defect  has,  to  a  great  extent,  been  rectified  ;  the  other  defect 
is  that  when  a  single  lens  is  made  to  embrace  too  wide  an  angle, 
straight  lines  in  the  subject  are  distorted  in  the  photograph. 
This  defect  has  been  greatly  exaggerated,  and  we  believe  that 
the  cases  where  the  use  of  a  "  single  "  lens,  used  at  moderate 
angle,  is  not  permissible,  are  much  more  rare  than  is  generally 
known  by  operators,  or  admitted  by  opticians.  For  por- 
traiture the  writers  have  found  the  "single"  lens  inferior  to 
no  other  type  of  lens,  but  it  is  advisable  that  the  single  lens, 
for  this  purpose,  be  made  to  work  with  as  wide  an  aperture, 
and  be  used  at  as  narrow  an  angle,  as  possible. 

"Group  lenses,"  so  called,  are  compromises  between  the 
portrait  and  the  rectilinear  types.  "Wide-angle  rectilinears  " 


THE   PROCESSES   OF   PURE    PHOTOGRAPHY.  23 

are  made  so  as  to  give  non-distorted  lines  while  working  at 
wide  angles.  Perhaps  the  type  of  lens  that  will  most  com- 
pletely meet  every  class  of  requirement  is  the  rapid  rectilinear, 
and  lenses  of  this  type  go  under  many  different  names  in  dif- 
ferent countries. 

The  focal  length  of  lens  necessary  to  cover  a  plate  may  be 
calculated  from  the  diagonal  of  the  plate.  In  cases  of  neces- 
sity, lenses  may  be  used  of  focal  length  less  than  the  diagonal 
of  the  plate,  but,  as  a  general  rule,  the  focal  length  ought  to 
be  at  least  50  per  cent,  over  the  length  of  the  plate. 

The  exposure  required  depends,  so  far  as  the  lens  is  con- 
cerned, entirely  on  the  proportion  of  the  area  of  aperture  to 
the  focal  length  at  which  the  lens  is  being  used.  If  a  lens  is 
focused  on  a  very  distant  object,  as  the  sun,  when  the  sun- 
image  is  in  focus  on  the  ground-glass  of  the  camera,  the  sun 
is  in  the  position  known  as  the  anterior  conjugate  focus  of  the 
lens,  and  the  ground-glass  is  at  the  posterior  conjugate  focus, 
or,  briefly,  the  solar  focus.  The  focus  of  a  lens  is  usually 
measured  from  the  "stop,"  in  case  of  a  combination  lens, 
from  the  lens  itself  in  the  case  of  a  single  lens,  to  the  ground- 
glass.  This  is  not  strictly  scientific.  But  if  we  focus  a  closer 
object,  say  ten  feet  off,  with  a  lens  of  about  four  inches  focus, 
principal  focus,  the  ground-glass  will  be  found  further  from  the 
leus  than  it  was  when  the  sun  was  focused  with  the  same  lens ; 
the  ground-glass  is  still  at  a  focus  of  the  lens,  but  it  is  not  the 
solar  focus,  and,  in  calculating  our  exposure  by  means  of  the 
proportion  of  aperture  to  focus,  it  is  not  the  sun  focus  we  have 
to  deal  with,  but  the  focus  of  the  object  which  we  are  focusing ; 
a  very  different  matter  in  the  case  of  close  objects.  From  inat- 
tention to  this  point  persons  are  often  greatly  deceived  in  their 
exposures  when  working  upon  near  objects.  The  proportion  of 
aperture  to  focal  length  is  usually  called  the  "  intensity  ratio," 
and  expressed  as  a  fraction  thus  :  -—  or  -j ,  x  being  the  focal 
length  in  inches,  and  the  numerator  of  the  fraction  being  the 
measure  of  the  aperture.  "Stops"  or  "diaphragms"  are 
always  sold  with  lenses  for  photography ;  these  stops  may  be 
separated  from  the  lens  and  used  by  being  placed  in  a  slot 
made  for  the  purpose  in  the  lens  tube,  or  they  may  be  fixed 


24  THE  PROCESSES   OF   PURE   PHOTOGRAPHY. 

to  the  lens  and  rotated  so  that  any  of  the  apertures  may  be 
used.  The  stops  are  usually  so  cut  as  to  give,  with  the  lenses 
to  which  they  belong,  intensity  ratios  as  follows :  {,  £  (these 
two  usually  confined  to  portrait  lenses) ;  |,  yf  .T,  T^-,  ^.-g-,  ¥^-, 
T£ y>  beyond  which  it  is  not  usual  nor,  indeed,  advisable  to  go, 
except  in  special  cases,  when  -/T  may  be  used.  These  terms 
simply  express  that  the  solar  focal  length  of  the  lens  is  4,  6,  8, 
11.3,  etc.,  times  the  diameter  of  the  aperture.  Exposures  are 
calculated  by  comparing  the  squares  of  the  denominators  of 
these  fractions.  If  at  ^  the  proper  exposure  is  found  to  be 
ten  seconds,  the  exposure  at  •/?  will  be  not  twenty  seconds 
but  forty  seconds. 

As  162  :  322  : :  10  :  40. 

In  calculating  exposures  for  close  objects,  the  caution  above 
given  as  to  real  focal  length  must  not  be  neglected.  Some  op- 
ticians number  their  stops  according  to  an  arbitrary  table  drawn 
up  by  a  committee  of  the  Photographic  Society  of  Great 
Britain.  A  table  will  be  found  at  the  end  of  this  book  show- 
ing the  connection  between  the  so-called  "  Uniform  System" 
of  numbering  stops  and — what  is  really  the  crucial  point — the 
intensity  ratios. 

For  the  special  province  called  instantaneous  photography, 
mechanical  "shutters"  are  required.  The  simplest  and  the 
oldest  is  the  "Drop"  or  Guillotine  shutter,  figured  No.  5, 


FIG.  5. 
wherein    a    loose  piece  with   an   aperture  falls  across    the 


THE   PROCESSES   OF   PURE   PHOTOGRAPHY.  25 

axis  of  the  lens,  the  shutter  being  placed  sometimes  on  the 
hood  or  front  of  the  lens,  sometimes  at  the  back  of  it.  As, 
usually,  it  is  desirable  to  expose  the  foreground  of  a  subject 
more  than  the  upper  part,  this  form  of  shutter  is  preferably- 
placed  behind  the  lens ;  for  if  it  is  in  front,  the  increasing 
velocity  of  the  f  ailing  plaque  of  wood,  metal,  or  other  material 
allows  the  foreground  less  exposure  than  the  upper  part. 

Shutters  of  this  type  should  have  their  aperture  by  no  means 
less  than  the  working  aperture  of  the  lens.  An  aperture  longer 
than  the  lens  diameter  is  recommended,  and  the  action  may  be 
quickened  by  an  elastic  spring. 

Many  shutters  are  used  in  the  centre  of  the  lens,  and,  in  cer- 
tain ways,  these  shutters  have  great  merits.  As  a  rule,  the 
apertures  of  these  shutters  are  of  square  or  diamond-shape,  and 
cross  each  other  in  the  act  of  exposure.  When  a  shutter  act- 
ing in  this  way  is  placed  either  in  front  or  in  rear  of  the  lens, 
the  inequality  of  lighting  inherent  in  certain  types  of  lenses  is 
exaggerated  ;  when  the  shutter  is  placed  in  the  centre  of  the 
lens,  not  only  is  this  defect  not  exaggerated,  but  the  result 


FIG.  6. 


is  better,  in  this  respect,  than  if  the  lens  were  used  with  the 
same  stop  and  the  lens-cap.  There  is  an  advantage  to  be  found 
in  shutters  opening  from  the  centre,  viz.,  that  the  loss  of  time 
occupied  in  opening  and  shutting  is  made  up  for  by  the  fact 


26  THE   PROCESSES   OF   PUKE   PHOTOGRAPHY. 

that  the  shutter  acts  during  part  of  the  exposure  as  a  stop. 
The  advantage  of  using  a  stop  is  that,  thereby,  greater  sharp- 
ness is  obtained  over  the  plate,  and  planes  of  the  subject  at 
various  distances  from  the  lens  are  brought  more  evenly  into 
focus  on  the  plate. 

The  markets  teem  with  shutters  for  instantaneous  exposures. 
If  the  purchaser  can  procure  one  which  will  work  without  jar 
during  the  exposure,  which  will,  at  will,  give  an  exposure  as 
short  as  one-hundredth  of  a  second,  or  as  long  as  half  a 


second ;  if  it  give  either  even  illumination  all  over  the  plate, 
or  extra  exposure  to  the  foreground;  if  it  allows  the  full 
amount  of  light  to  act  on  the  plate  during  the  greater  part  of 
the  duration  of  its  working  («  co-efficient  of  light  ")  ;  and  if,  in 
addition,  it  can  be  made  to  give  an  exposure  regulated  by  the 


THE   PROCESSES   OF   PURE   PHOTOGRAPHY.  27 

hand  of  the  worker,  that  purchaser  will  not  regret  his  pur- 
chase. It  would  be  invidious,  from  such  a  number  of  good 
shutters,  to  single  out  any  one  as  the  best,  but  we  give  figures 
(6  and  7)  of  two  good  shutters,  one  well  known  in  America, 
the  other  in  Great  Britain. 

With  the  ordinary  lens-cap,  by  hand,  an  exposure  can  be, 
with  a  little  practice,  made  not  exceeding  one-fourth  or  one- 
fifth  of  a  second,  but  the  performance  is,  in  some  hands,  risky. 

It  will  be  noticed  that  as  yet  we  have  not  written  a  word  of 
suggestion  as  to  size,  nor  do  we  propose  to  more  than  allude 
to  the  matter.  The  photographer  must  choose  the  size  for 
himself,  according  to  his  bank  account,  his  bodily  rigour,  his 
available  leisure,  and  his  object.  Expense,  exertion,  and  at- 
tention required,  all  increase,  at  an  enormous  rate,  as  size  of 
work  increases.  The  smallest  size  commonly  used  is  known  as 
"  quarter-plate,"  the  size  of  plate  being  4Jx3^  inches.  The 
impedimenta  for  work  of  this  size  are  not  worth  mention, 
and  the  expense  moderate.  By  an  easy  process  lantern  slides 
can  be  produced  from  quarter-plate  negatives,  and  we  doubt 
whether  we  could  name  a  nobler  finale  to  a  set  of  photographic 
operations  than  a  good  lantern-slide,  for  which  we  shall  give 
very  careful  instructions  in  this  book. 

"  Half-plate,"  6£x4f  (in  England),  6£x4^  (in  America),  is, 
perhaps,  the  smallest  size  from  which  a  direct  print  can  be 
made  that  will  not  look  trivial. 

"  Whole-plate,"  8£x6^  inches,  is  a  very  convenient,  and  in 
our  opinion,  elegant  size. 

The  largest  size  we  can  recommend  for  amateurs,  in  a  general 
way,  is  10x8  inches,  which  most  persons  will  find  auite  enough 
to  carry  into  the  field. 

For  portraiture,  where  weight  is  a  matter  of  no  consideration, 
we  recommend  the  largest  size  the  would-be  'purchaser  can 
afford.  We  confess  ourselves  sick  of  the  everlasting  "  cabinet " 
portrait,  and  its  little  brother,  the  "  carte."  If  the  amateur 
must  trespass  on  the  domain  of  the  professional,  let  him  do 
so  «  en  grand  seigneur." 

Besides  such  necessaries  as  we  have  touched  upon,  there  are 


28 


THE    PROCESSES    OF    PUBE   PHOTOGRAPHY. 


a  number  of  smaller  articles  which  will  be  required.     These 
we  shall  merely  advert  to. 

A  cloth,  known,  too  often,  as  the  "black  cloth,"  or  "black 
rag,"  is  used  to  cover  the  camera  while  focusing  is  being  done. 
This  cloth  looks  much  better  when  dark-colored,  but  not  black, 
and  waterproof  cloth  is  far  superior  to  velvet,  because  it  is 


FIG.  8. 


waterproof,  and  often  useful  in  that  capacity  ;  because  it  has  a 


better  appearance,  and  because  it  does  not  cling  to  the  cap,  or 
air,  when  the  head  is  being  withdrawn  from  under  it.     The 


THE   PROCESSES   OF   PURE   PHOTOGRAPHY.  29 

cloth  should  be  tied,  or  buttoned,  on  to  the  camera  front,  and 
should  be  of  ample  size. 

Dishes  for  development  of  ordinary  dry-plates  should  be 
black,  and  papier-mache  is  perhaps  the  best  material.  To  save 
extra  quantity  of  solution  the  bottom  should  be  flat,  but  in 
order  to  avoid  staining  the  fingers  in  lifting  the  plate  up  for 
examination,  either  a  hook  must  be  used,  or  the  dish  made 
with  ridges  at  bottom.  For  other  operations,  as  "  toning," 
porcelain  dishes  are  to  be  preferred.  For  the  smaller  sizes, 
glass  dishes  are  found  very  elegant,  but  they  have  the  defects 
of  weight  and  brittleness. 

Graduated  measures  of  different  sizes,  scales  and  weights, 
filter-funnels,  and  other  laboratory  requisites  are  necessary  in 
small  quantities,  but  need  no  remark. 


FIG.  9. 


Plate  boxes  for  storing  sensitive  plates  must  be  made  care- 
fully light-tight,  and  of  such  wood  or  other  material  as  will 
not  affect  the  most  sensitive  plates  (Fig.  9). 


FIG.  10. 

A  rack  for  drying  plates  is  preferable  to  leaning  the  plates 
against  a  wall,  or  other  object  to  dry  (Fig.  10). 

Other  apparatus  will  be  described,  as  the  need  for  it  turns  up, 
in  our  future  chapters. 


CHAPTER  IV. 
THE   DARK-ROOM. 

THE  above  is  the  name  technically,  but  not  accurately,  given 
to  the  apartment  wherein  are  conducted  such  operations  as 
would  be  hurt  or  impossible  in  actinic  light,  by  reason  of  its 
action  upon  our  sensitive  salts,  as  described  briefly  in  Chapter 
II.  The  requirements  of  an  operating-room  are  of  the  sim- 
plest, but  it  may  not  be  amiss  to  give  a  few  hints  as  to  the 
easiest  and  best  way  to  arrange  an  apartment  for  the  purposes 
with  which  we  propose  next  to  deal. 

Many  amateurs  find  it  impossible  or  highly  inconvenient  to 
secure  an  apartment  of  any  kind  for  their  work,  and  for  such  a 
"  dark-tent "  may  be  the  most  convenient  way  out  of  the  diffi- 
culty. But  it  is  probable  that  each  of  our  readers  will  be  able 
either  to  adapt,  or  to  find,  or  to  build  an  apartment  for  his 
photographic  requirements. 

If  a  room  is  to  be  used  only  occasionally  or  temporarily  as 
an  operating-room,  the  most  required  will  be  to  stop  out  all 
white  light  by  whatever  means  appear  most  handy.  .A  window 
may  either  be  blocked  up  entirely  by  opaque  material,  such  as 
thick  brown  paper,  or  brown  paper  in  several  layers,  or  it 
may  be  preferable  to  block  out  the  light  only  partially  with 
opaque  material,  and  allow  some  light  into  the  room  through 
some  medium,  such  as  ruby  glass  or  orange  or  yellow  paper. 
The  color  and  thickness  of  .these  light-filtering  media  depend 
on  the  sensitiveness  of  the  photographic  substances  we  propose 
to  use.  For  wet  collodion,  dry  collodion,  or  gelatine-chloride 
plates,  yellow  glass  or  lemon- colored  paper  will  be  sufficient  pro- 
tection, even  from  daylight.  For  processes  wherein  we  use  gela- 
tine-bromide of  silver  in  a  moderate  state  of  sensitiveness,  as  for 
"lantern-slides,"-  «  bromide  prints,"  or  "slow  gelatine-bromide 


THE  PROCESSES    OF   PURE    PHOTOGRAPHY.  31 

plates,"  an  orange-colored  filtering  medium,  a  single  ruby  glass, 
or  "  canary  medium  "  may  be  used.  With  very  rapid  gelatine- 
bromide  plates  we  must  use  several  thicknesses  of  orange  or 
canary  paper,  or  we  must  add  to  the  ruby  glass  a  thickness  of 
yellow  glass.  If  we  are  going  to  expose  our  sensitive  mate- 
rial to  the  light  for  a  prolonged  period,  as  in  emulsion-making, 
we  must  redouble  our  precautions  in  this  line,  and  for  ortho- 
chromatic  work  (see  Chapter  XVIII),  we  must  not  only  restrict 
ourselves  to  ruby  light,  but  we  must,  as  far  as  possible,  restrict 
the  quantity  of  that.  If  there  be  any  doubt  as  to  the  "  safety  " 
of  our  light,  we  should  expose  a  sample  of  the  material  with 
which  we  are  working  under  a  "  sensitometer  screen,"  or  under 
a  negative,  to  the  suspected  light,  and  ascertain  by  develop- 
ment whether  any  light-action  takes  place.  We  may  place  one 


FIG.  11. 

of  our  plates  in  a  book,  so  that  part  is  protected  by  the  book 
and  part  exposed  to  the  suspected  light  for  (say)  five  minutes. 
If,  on  development,  any  action  is  observed  on  the  exposed  part 
it  is  evident  that  further  precaution  must  be  taken  with  regard 
to  the  light. 

Alternatively,  and  perhaps  preferably,  the  light  may  be  en- 
tirely, blocked  out  of  the  room,  and  a  "  non-actinic  lamp  "  used. 
The  variety  of  these  in  the  market  is  infinite.  We  figure  one 
only,  Fig  11. 

If  gas  is  laid  on,  we  recommend  the  principle  of  building  a 
lantern  around  a  jet,  so  that  (1)  the  heated  air  and  combustion- 


32  THE   PROCESSES    OF    PUKE   PHOTOGRAPHY. 

products  are  carried  right  out  of  the  apartment,  if  possible  ; 
(2)  the  gas  can  be  raised  or  lowered  from  the  outside  of  the 
lantern. 

In  the  case  of  a  room  temporarily  used  as  an  operating- 
room,  it  is  well  to  cover  the  tables  with  waterproof  or 
"  American  "  cloth.  A  basin  or  foot-pail  may  serve  as  a  sink, 
and  any  vessel  of  suitable  size  and  shape  may  be  "  annexed  " 
for  water.  We  have,  in  a  hotel  bedroom  in  Italy,  made  rapid 
gelatine  emulsion,  coated,  dried  and  developed  plates,  with 
some  little  exercise  of  ingenuity,  but  without  accident  or 
failure. 

But  we  venture  to  say  that  success  will  most  likely  at- 
tend operations  conducted  in  apartments  made  or  adapted 
solely  for  the  purpose  of  these  operations.  The  apart- 
ment chosen  or  built  must  be  thoroughly  ventilated  as  well 
as  thoroughly  light-proof,  otherwise  the  accruing  vapors  will 
damage  both  the  health  and  the  success  of  the  operator. 
A  north  aspect  should,  if  possible,  be  chosen  for  the  win- 
dow. A  window  should  exist  in  the  room,  whether  that 
window  is  to  be  used  for  the  photographic  operations  or 
whether  it  is  to  be  blocked  up  during  operations.  The  system 
of  dark-room  lighting,  which  we  find  most  satisfactory,  is  to 
have  our  window  glazed  with  perfectly  safe  light,  but  to  have, 
also,  our  gas  lantern  lighted  and  worked  from  the  outside.  We 
commence  developing  operations  by  daylight  filtered  through 
our  "  safe  "  window,  and  when  we  come  to  the  point  where 
critical  examination  is  required,  we  turn  up  our  non-actinic  gas 
lantern,  which  is  provided  with  various  filtering  media — viz., 
clear  ruby  glass  at  one  side,  canary  medium  paper  at  another, 
and  ruby  glass,  ground  on  one  side,  at  another.  Ruby  glass 
ground  on  one  side  is  one  of  the  most  perfect  media  we  know. 
Of  "  ruby  glasses,"  the  safest  sample  we  have  ever  seen  was 
ordinary  "metal-flashed  ruby  "  on  one  side  and  "  stained  yellow" 
on  the  other  side.  Some  persons  cannot  tolerate  ruby  color  ; 
others  dislike  yellow-greens.  The  ruby  tints  are  used  clear, 
and  often  combined  with  clear  yellows.  The  yellow  media 
require  the  light  to  be  more  or  less  diffused,  either  by  paper  or 
ground-glass,  or  semi-obscured  glass  in  some  form  or  other.  Of 


THE    PROCESSES   OF   PUKE    PHOTOGRAPHY.  33 

course,  a  medium  that  may  be  "  safe "  with  artificial  light 
might  be  disastrous  if  used  with  daylight ;  and,  moreover,  a 
medium  safe  with  daylight  in  mid  winter  may  be  fatal  in 
spring  or  summer.  The  test  recommended  above  is  equally 
useful  here. 

The  sink  for  an  operating-room  is  often  made  of  stoneware, 
often  of  iron.  We  greatly  prefer  wood  lined  with  sheet-lead, 
which  does  not,  perhaps,  look  so  pretty,  but  does  not  fracture 
a  measure  knocked  over  or  laid  too  briskly  down  on  it. 

The  tap  should  be  of  the  "  arm  "  kind,  but  the  turning  of 
the  arm  must  not  regulate  the  water-flow ;  there  should  be  a 
cock  to  turn  the  water  on  and  off. 

On  one  side,  at  least,  of  the  sink,  and  projecting  slightly 
over  the  sink,  should  be  a  table,  lead-lined,  and  sloping  down 
towards  the  sink.  This  is  to  receive  dripping  measures,  dishes, 
plates,  etc.,  and  to  carry  the  drip  into  the  sink.  A  slightly- 
raised  ledge,  or  "beading,"  round  the  table,  will  prevent 
liquids  reaching  the  floor. 

Shelves,  cupboards,  tables,  etc.,  are  evident  requirements  of 
an  operating-room.  Hot  water  supply  is  an  immense  boon. 
A  fixed  syphon  trough  for  washing  negatives  is  a  great  con- 
venience. 

The  nozzle  of  the  tap  should  end  in  a  thread,  to  which,  by 
means  of  a  gas  coupling,  can  be  attached  a  variety  of  small 
apparatus,  as  a  rose  tap — an  invaluable  article — a  rubber 
tube,  etc. 

Drying  presses  and  other  matters  shall  be  described  as  their 
uses  are  treated. 

The  dark-room  should  be  kept,  as  far  as  possible,  at  an  even 
and  moderate  temperature.  Whatever  be  the  fuel  used  the 
products  of  combustion  must  be  carried  right  out  of  the  room. 
Gas,  in  particular,  has  a  noxious  effect  on  many  of  our 
products. 


CHAPTER  V. 
"NEGATIVE"  AND  "POSITIVE." 

THE  result  of  every  set  of  photographic  operations  is  either 
a  positive  or  a  negative.  A  "  positive  "  shows  the  light  colors 
in  nature  as  whites,  the  shadows  as  dark,  while  a  "negative" 
shows  the  high  lights  of  nature  as  dark,  the  shadows  as  light. 
A  positive  may  be  looked  either  at  or  through,  a  negative  is 
not  intended  for  looking  at,  but  is  merely  intended  to  be 
printed  through,  so  as  to  produce  what  is  always  our  ultimate 
object — a  positive.  Positives  are  very  seldom  now  produced 
direct  from  nature,  they  are  almost  always  produced  through 
the  intervention  of  negatives.  A  negative  is  of  no  value  or 
merit  irrespective  of  the  value  or  merit  of  the  positives  which 
may  be  produced  from  it. 

We  have  to  deal  with  "  positives "  as  prints  on  paper,  on 
opal,  or  on  other  opaque  or  semi-opaque  supports  ;  and  with 
'  transparent  positives,"  as  "  lantern-slides,"  window  transpar- 
encies, etc. 

"VEHICLE"  AND  "SUPPORT." 

We  require  for  our  sensitive  salts  (1)  a  substance  wherein 
they  may  be  suspended,  because  we  cannot,  in  practice,  spread 
or  use  them  on  a  hard,  repelling  surface,  such  as  glass.  The 
suspending  substance  is  called  the  u  vehicle,"  and  may  be  col- 
lodion, albumen,  gelatine,  paper,  or  other  substances.  (2) 
Some  "  support,"  to  hold  our  suspended  sensitive  substances 
in  such  a  layer  and  condition,  that  we  may  expose  a  consider- 
able surface  of  our  sensitive  substances  to  light-action,  and  be 
able,  thereafter,  to  manipulate  them.  Glass  is  the  commonest 
"  support "  now  in  use,  but  we  have,  also,  acting  as  supports, 
paper,  gelatine  films,  metal  plates,  etc.,  etc. 


THE  PROCESSES  OF  PUKE  PHOTOGRAPHY.          35 

The  support  may  be  "  temporary,"  as  in  cases  where,  after 
operations  are  complete,  we  strip  our  vehicle,  with  its  sus- 
pended substances,  from  the  temporary  support ;  or  the  sup- 
port may  be  "  permanent,"  as  in  the  cases  of  the  glass  of  our 
ordinary  negatives,  or  the  paper  of  our  ordinary  prints. 
Paper,  among  other  substances,  may  be  at  once  vehicle  and 
support,  temporary  support  and  permanent  support. 

We  propose  first  to  deal  with  the  wet  collodion  process, 
which  may  be  ifsed  as  (1)  a  negative  process,  (2)  a  transparent 
positive  process,  as  in  the  case  of  lantern-slides,  (3)  an  opaque 
(or  simply)  positive  process.  As  the  use  of  wet  collodion, 
under  Ko.  3,  is  now  rare  and  confined  to  the  production  of 
positives  not  remarkable  for  excellence  at  the  best,  we  shall 
not  do  more  than  allude  to  it  under  this  heading. 

We  cannot  do  the  wet  collodion  process  full  justice,  as  we 
are  well  aware,  in  our  limited  space,  but  the  process  is  so  inter- 
esting, so  educative,  and  so  beautiful  in  many  of  its  results, 
that,  though  of  late  years  it  has  fallen  into  comparative  disuse, 
we  feel  impelled  by  our  own  wish,  as  well  as  for  the  good  of 
our  readers,  to  devote  some  space,  however  unworthy  of  its 
merits,  to  the  process. 


CHAPTER  VI. 
THE  WET  COLLODION  PROCESS. 

IN  this  process  collodion  forms  the  vehicle,  glass  the  sup- 
port, and  silver  haloids  the  sensitive  salts.  The  latter  salts 
are  formed  in  the  vehicle  by  the  chemical  action  known  as 
"  double  decomposition."  The  vehicle  at  first  holds  in  suspen- 
sion an  iodide  (as  of  potassium),  or  a  bromide,  or  a  chloride, 
or  all  three ;  these  halogens,  coming  in  contact  with  silver 
nitrate  in  solution,  combine  with  the  silver  to  form  the  silver 
haloids  in  the  vehicular  film  of  collodion,  and  these  haloids  are 
the  salts  that  receive  the  light-action,  and  determine  another 
action  known  as  development,  which  is  really  a  reduction  of 
the  silver  to  the  metallic  state.  It  is  utterly  impossible,  in  a 
few  words,  to  explain,  even  in  outline,  a  series  of  chemical 
actions  such  as  this;  the  safer  way,  for  all  parties,  will  be 
not  to  attempt  desultory  and  partial  theory. 

Collodion  is  a  solution  of  gun-cotton  in  ether  and  alcohol, 
and  is  sold  ready  for  our  purpose  either  "iodized"  or  with  a 
separate  bottle  of  "  iodizer,"  to  be  mixed  with  the  plain  collo- 
dion, according  to  instructions.  As  a  rule  there  is,  along  with 
the  iodide,  a  certain  proportion  of  bromide,  and  for  landscape 
work  a  good  proportion  of  bromide  is  desirable. 

A  plate  of  glass,  being  thoroughly  cleaned,  is  "  coated  "  with 
iodized  collodion,  and  is  thereafter  immersed  in  a  solution  of 
silver  nitrate.  The  now  sensitized  plate  is  exposed  in  the 
camera,  brought  back  to  the  operating-room,  where  it  was 
sensitized  in  non-actinic  light,  flooded  with  a  developer,  con- 
sisting of  a  salt  of  iron  in  solution,  washed,  *•  fixed,"  and 
washed  again,  when  it  is  supposed  to  be  a  finished  negative. 
To  take  these  operations  in  detail : 

Cleaning  the  Glass  Plate  is  usually  performed  with  a  mix- 


THE   PROCESSES    OF    PURE   PHOTOGRAPHY.  37 

ture  of  alcohol  and  ammonia,  containing  a  little  rouge  powder 
or  tripoli.  If  the  plate  has  been  used  previously,  the  cleaning 
must  be  performed  with  all  the  more  care,  and  a  preliminary 
bath  of  nitric  acid  and  water  is  desirable  ;  in  any  case,  the 
plate,  back  and  front,  must  be  scrupulously  clean  and  free  from 
the  slightest  trace  of  grease  or  organic  matter  of  any  kind. 
Sometimes  the  plate  is  flowed  twice  with  albumen  thinned 
with  water  and  alkalized  with  ammonia,  and,  of  course,  most 
carefully  filtered ;  this  is  preferable  to  having  a  dirty  plate, 
but  is  apt  to  disorder  the  silver-bath.  After  the  plate  is 
cleaned,  it  must  be  "polished"  with  a  scrupulously  clean 
chamois  leather.  The  plate  must  not  be  rubbed  with  silk 
immediately  before  coating. 

Coating  the  Plate  with  Collodion. — This  is  an  operation 
which  requires  both  care  and  practice.  In  no  process  of  pho- 
tography is  more  attention  to  apparently  trivial  details  re- 


FIG.  12. 

quired  than  in  the  wet  collodion  process ;  absolute  cleanliness, 
freedom  from  dust,  and  method  are  required  at  every  step. 
The  first  crucial  operation  is  that  of  "  coating  the  plate." 
The  collodion  containing  the  "  iodizing  "  agents  must  be  kept 
clear  of  dust,  free  from  solid  particles  of  collodion,  in  a  bottle 
of  such  form  as  to  permit  of  neat  and  even  pouring,  and 
to  prevent  solid  or  semi-solid  particles  'from  settling  on  the 


38 


THE   PROCESSES   OF   PUKE   PHOTOGRAPHY. 


plate.  A  suitable  bottle  is  shown  in  Fig.  12.  The  collodion 
must  run  evenly  over  the  whole  of  the  face  of  the  plate,  must 
run  over  no  part  twice,  nor  stop  for  any  considerable  time  on 
any  part.  The  operation  is  performed  in  the  following  way, 
and  those  uninitiated,  yet  unwilling  to  waste  collodion,  may  try 
their  "  prentice  hands  "  with  milk  or  thin  cream. 

The  polished  plate  is  taken  by  one  extreme  corner,  or,  much 
preferably,  on  a  pneumatic-holder  scrupulously  clean  (Fig.  13). 


FIG.  13. 


The  face  and  back  are  quickly  dusted  with  a  camel's-hair 
brush,  and  the  plate  held  in  the  left  hand  in  the  position 
shown  in  the  figure,  A  E  being  next  the  operator's  body. 


FIG.  14. 

A  pool  of  collodion  is  poured  about  the  point  A  in  sufficient 
quantity  to  more  than  cover  the  whole  plate,  the  pool  as  it 
widens  is  guided  by  tilting  the  plate  slowly  but  steadily 
towards  B,  then  around  towards  C,  then  towards  A;  the  now 
broad  wave  is  directed  towards  D,  at  which  corner  it  is  poured 
ie  plate  into  a  second  bottle,  through  a  filter  if  convenient 


THE  PROCESSES  OF  PUKE  PHOTOGRAPHY.          39 

The  plate,  while  the  collodion  is  running  off,  must  be  gently 
and  slowly  rocked  by  depressing  alternately  corners  E  and  B, 
and  the  corner  E  may  be  gently  touched  by  the  neck  of  the 
second  bottle,  or  the  filter,  but  must  on  no  account  be  ground 
against  any  hard  substance.  When  the  collodion  is  "  tacky," 
or  takes  the  impression  of  the  skin  of  the  finger  at  corner  D, 
the  plate  must  without  delay  be  placed  in  the  "  nitrate  bath." 
Many  operators  hold  the  plate,  while  coating  it,  with  the 
narrow  end  next  the  body,  pouring  the  pool  of  collodion  near 
the  right  top  corner ;  some  pour  it  on  near  the  left  side  next 
the  body,  but  we,  after  considerable  experience,  prefer  the 
method  we  have  given. 

The  "Silver  Bath"  or  "Sensitizing  Bath"  is  as  simple 
to  make  as  it  is  difficult  to  keep  in  order.  Therefore,  it  should 
be  made  in  two  batches  at  once,  one  solution  to  replace  the 
other  when  the  first  used  goes  wrong : 

Silver  nitrate  (crystallized) 35  grains 

Pure  water 1  ounce 

in  sufficient  quantities,  of  course,  to  cover  the  plate  thor- 
oughly in  the  bath.  This  is  the  most  generally  useful  strength, 
and  the  limits  of  variation  are  but  small.  Very  cold  weather 
may  indicate  a  bath  five  grains  per  ounce  stronger.  A  trace 
of  iodine  must  be  added  to  this  bath,  either  by  adding  for 
every  ten  ounces  of  "  bath  solution  "  about  a  grain  of  potas- 
sic  iodide  direct,  or  by  coating  a  plate  with  iodized  collo- 
dion and  leaving  in  the  bath  for  some  hours.  If  the  addi- 
tion of  iodide  be  neglected,  pinholes  (tiny  transparent  spots) 
will  surely  affect  all  the  plates  first  sensitized  in  the  bath. 
The  water  must  be  absolutely  free  from  organic  matter ; 
water  distilled  in  a  glass  or  clean  metal  "  still  "  will  answer, 
or  rain  water  caught  direct  from  the  clouds  in  a  clean — not 
metal  or  wood — vessel.  Even  rain  water  is  not  entirely  to  be 
trusted.  A  crystal  of  silver  nitrate  should  be  placed  in  about 
a  pint  of  rain  water,  the  vessel  containing  it  allowed  to  stand 
some  days  in  bright  light,  and  the  water  carefully  filtered 
through  pure  filter  paper.  To  prepare  the  bath :  Dissolve  the 
full  quantity  of  silver  nitrate  in  about  one-half  the  full  quantity 


40          THE  PROCESSES  OF  PURE  PHOTOGRAPHY. 

of  water,  add  the  iodide  if  the  addition  is  to  be  made  directly  ; 
then  make  up  with  water  to  full  bulk,  and  filter. 

The  "bath"  is  at  all  times,  after  long  use,  liable  to  become 
supersaturated  with  either  (1)  iodine,  or  (2)  collodion  solvents 

ether  and  alcohol.    No.  1  is  indicated  by  "  pinholes  "  in  the 

negatives ;  to  cure  this,  dilute  the  bath  to  half  its  strength, 
make  up  to  original  strength  with  silver  nitrate,  and  filter  care- 
fully. If  No.  2  be  indicated  by  unequal  sensitizing  and 
streaky  development,  the  application  of  heat  will  drive,  off  the 
offending  solvents.  A  third  adulteration,  that  of  organic  mat- 
ter, is  more  difficult  to  get  rid  of  ;  it  will  be  indicated  by  fog, 
"  veil,"  dirty  negatives,  etc.  To  remove  organic  matters 
which  get  into  the  bath  from  the  fingers,  the  clothes,  the  at- 
mosphere, or  dirty  plates,  make  the  solution  distinctly  alkaline 
with  sodic  carbonate,  and  place  the  solution  in  a  strong  light 
for  some  days,  after  which  filter  out  the  black  deposit,  re- 
acidify  with  nitric  or  acetic  acid,  and  filter  again. 

The  sensitizing  bath  must  never  be  used  alkaline ;  it  must 
be  tested  for  acidity  with  blue  litmus  paper.  If  the  paper  does 
not  turn  red,  acid — nitric  or  acetic — must  be  added  to  the  bath 
till  the  paper  shows  distinct  redness.  For  negative  work, 
acetic"  acid  is,  perhaps,  preferable  ;  for  positives,  nitric  acid. 

When  the  collodion  has  "  set "  on  the  plate,  as  described — the 
time  requisite  for  setting  depending  chiefly  on  the  temperature, 
and  varying  from  twenty  seconds  upwards — the  plate  is  to  be 
immersed  in  the  "  bath." 

Two  kinds  of  receptacles  are  used  for  the  bath  solution.  In 
some  countries  we  find  the  dipping  bath  almost  in  universal 
use ;  in  other  countries  an  ordinary  flat  porcelain  or  glass  dish 
is  used.  The  dipping  bath,  figured  at  No.  15,  requires  a 
"dipper"  of  silver,  porcelain,  or  varnished  wood  (the  last 
not  strongly  recommended),  and  it  also  necessitates  a  much 
larger  quantity  of  solution  than  the  flat  dish,  but  it  has  the 
advantage  of  better  protecting  the  plate  and  the  solution  from 
dust  and  other  impurities.  We  leave  the  choice  to  our  readers, 
saying  only  that,  having  used  both,  we  prefer,  on  the  whole, 
the  flat  dish,  keeping  it  carefully  covered  and  the  solution  fre- 
quently filtered.  The  plate  is  to  be  immersed  in  the  solution 


THE  PROCESSES  OF  PUKE  PHOTOGRAPHY.          41 

steadily,  without  either  a  sudden  plunge  or  a  hesitating  stop- 
page, and  the  lower  end  of  the  plate,  where  the  collodion  is 
probably  thicker,  is  to  be  immersed  h'rst.  In  a  few  seconds  a 
change  will  be  seen  on  the  plate,  a  kind  of  gray  or  bluish-gray 
film  appearing,  due  to  the  formation,  by  "double  decompo- 
sition," of  the  silver  haloids.  After  the  plate  has  been  in  the 
bath  about  forty -five  seconds,  the  thick  collodion  end,  if  in  a 
flat  dish,  the  whole  plate  on  the  dipper,  if  in  a  dipping  bath, 
should  be  gently  and  only  slightly  raised.  The  sensitization  is 
complete  when  there  is  no  longer  any  appearance  of  "  greasi- 
ness"  on  the  plate,  that  appearance  being  due  to  the  collodion 


FIG.  15. 

solvents.  The  plate  should  now  be  covered  with  a  perfectly 
even  film  of  gray  or  bluish-gray  (according  to  the  salts  in  the 
collodion)  color.  Of  course,  the  sensitizing -of  the  plate  must 
be  done  in  non-actinic  light — in  the  present  case  yellow  glass, 
or  even  a  candle  shaded  by  yellow  paper  will  afford  sufficiently 
safe  illumination. 

The  plate,  now  sensitive,  is  raised  from  the  bath  slowly,  the 
drops  at  the  lower .  end  blotted  off  on  clean  filter  or  blotting 
paper,  the  back  wiped  with  similar  paper,  and  the  plate  is 
placed  in  the  dark-slide,  propped  up  in  the  position  it  will 
occupy  in  the  camera.  The  plate  being  placed  in  position, 
film  to  the  front  and  against  the  silver  or  glass  corners  in  the 
slide,  a  piece  of  red  blotting  paper,  which  may  with  advantage 
be  damped,  is  placed  behind  the  plate,  and  the  slide  is  closed. 


42  THE   PROCESSES    OF    PUKE    PHOTOGRAPHY. 

As  a  rule,  the  thicker  part  of  the  collodion  film  should  be 
placed  at  the  upper  part  of  the  dark-slide  which  will  receive 
the  foreground  of  the  picture.  The  slide  once  charged  in  its 
proper  position  must  never  be  waved  about  nor  reversed  so  as 
to  cause  the  silver  solution  to  run  back  over  the  plate  ;  it  must 
be  carried  steadily,  and  if  laid  down  must  preserve  the  position 
in  which  it  was  charged. 

We  then  proceed  to  make  an  exposure  (see  Chapter  XIII.)^ 
and  after  exposure,  return  to  the  dark-room  with  the  slide, 
which  we  again  prop  up  in  its  former  position,  till  we  are 
ready  to  develop  the  plate. 

Development.  —  An  average  iron  developer  may  be  formu- 
lated thus: 

Iron  protosulphate  ..............................   12  grains 

Acetic  acid  (glacial)  ........................  ----   30  minims 

Water  ...........................................     1  ounce 

Alcohol  ........................................   q.  s. 

For  the  acetic  acid  we  may  substitute  nitric  acid,  1  minim. 
The  quantity  of  alcohol  is  regulated  by  the  amount  of  alcohol 
in  the  bath,  a  new  bath  necessitates  almost  no  alcohol  in  the 
developer  ;  as  the  bath  ages,  so  the  alcohol  in  .the  developer 
must  be  increased,  otherwise  streaks  will  appear. 

The  iron  protosulphate  must  be  fresh,  and  of  a  fine  green 
color;  the  yellow  crust,  often  seen,  is  due  to  oxidation,  and 
does  mischief  acting  as  a  restrainer  (Abney).  The  propor- 
tions of  iron  may  vary  greatly  ;  as  little  as  five  grains,  and  as 
much  as  forty  grains,  to  each  ounce,  may  be  used  under  certain 
conditions.  One  of  the  writers  used  with  great  satisfaction,  in 
Italy,  the  following  : 

Ammonia  sulphate  of  iron  ........................  77  grains 

Aceticacid  ..................  .  ..................   70  minims 

Alcohol 


q    s 

3  ounces 


The  acid  is  in  each  case  used  as  a  "restrainer  "  or  "retarder." 
Without  it  the  image  would  flash  out,  fog,  and  be  not  only 
uncontrolable,  but  useless. 

The  plate  is  taken  out  of  the  slide  by  "  safe  "  light,  prefer- 


THE  PROCESSES  OF  PUKE  PHOTOGRAPHY.          43 

ably  with  the  pneumatic  holder  (vide  supra\  is  held  over  the 
sink  with  the  thicker  end  of  the  collodion  film  next  the  oper- 
ator. Sufficient  of  the  developer,  amply  to  cover  the  plate,  is 
taken  in  a  cup,  and  swept  over  the  plate  in  one  wave,  not  vio- 
lently, but  without  hesitation  ;  if  possible,  no  solution  should 
be  spilled.  This  is  allowed  to  move  over  the  plate  for  half  a 
minute,  more  or  less,  and  is  then  poured  off  into  the  sink,  or 
into  a  residue  jar.  If  the  image  flashes  up  gray,  the  exposure 
has  been  too  great ;  if  it  comes  up  reluctantly,  or  black  and 
white,  or  not  at  all,  the  exposure  has  been  too  short,  in  each 
case  supposing  the  "  bath "  and  the  developer  in  proper 
order.  In  place  of  acid,  certain  viscous  substances  are  some- 
times used  as  "retarders"  of  development,  making  the  de- 
veloping solution  more  "  syrupy,"  and  so  offering  more  resist- 
ance to  the  solid  particles  traveling  through  it.  Among  sub- 
stances recommended  for  this  purpose  are  sugar,  glycerine, 
gelatine,  and  the  "  collocine  "  of  Mr.  Carey  Lea. 

He-development. — It  is  probable,  especially  if  the  wave  of 
developer  carries  any  solution  over  the  edge  of  the  plate,  that 
the  image,  after  development,  will  not  be  dense  enough  for 
printing  purposes,  and  possible  that  there  may  be  a  lack  of  de- 
tail, as  well  as  of  density.  In  this  case  the  plate  is  washed 
under  the  tap,  and  a  further  dose  of  developer  is  applied,  with 
the  addition,  this  time,  of  some  silver  nitrate.  To  each  ounce 
of  the  fresh  developer,  in  the  cup,  we  may  add  ten  or  twelve 
drops  of  a  ten  per-cent.  solution  of  silver  nitrate.  (Silver 
nitrate  forty-eight  grains,  water  up  to  one  ounce,  acidified 
with  nitric  acid.)  This  is  applied  to  the  plate,  and  allowed  to 
move  over  it  as  before,  density  and  detail  will  both  increase. 
If,  after  development,  the  image  is  weak,  and  wants  detail,  re- 
development is  wanted ;  if  weak,  and  full  of  detail,  it  is  contra- 
indicated.  In  the  latter  case  intensification  (see  p.  44)  is  in- 
dicated as  necessary. 

Fixing. — The  plate,  after  re-development,  is  again  washed 
and  fixed  (i.  e.,  the  unaltered-by-light  silver  salts  are  dissolved) 
by  pouring  on  either  : 

Potassic  cyanide 25  grains 

Water.  . .  .1  ounce 


44         THE  PROCESSES  OF  PURE  PHOTOGRAPHY. 

Or, 

Sodic  hyposulphite 100  grains 

Water 1  ounce 

till  the  yellow  veil  disappears  from  the  plate  entirely. 

The  potassic  cyanide  is  highly  poisonous,  even  by  absorp- 
tion, its  fumes  are  noxious  to  some  persons ;  the  sodic  salt  is 
harmless.  After  the  plate  is  perfectly  "  fixed  "  or  "  cleared  " 
it  must  be  carefully  washed,  especially  after  "  hypo." 

Intensification  is  resorted  to  for  plates  that  are  wanting  in 
density,  and  consists  of  an  operation  very  similar  to  re-devel- 
opment ;  the  same  solution  may  be  applied  as  for  re-develop- 
ment, or  the  iron,  this  time,  may  be  replaced  by  three  grains  of 
pyrogallic  acid.  The  silver  nitrate  is  to  be  added  as  before  in 
re-development.  The  plate  is  finally  washed  and  allowed  to 
dry.  Drying  before  a  fire  will  slightly  increase  the  density. 

These  processes  are  practically  the  same  for  a  transparent 
positive  (as  a  lantern  slide)  as  for  a  negative.  The  wave  of 
developer  may  be  allowed  to  carry  a  little  solution  over  the 
edge  of  the  plate,  and  any  increase  of  density  must  be  admin- 
istered with  caution. 

The  collodion  film  is  very  delicate,  and  requires  to  be  pro- 
tected by  a  varnish  usually  composed  of  gums  dissolved  in 
spirits.  Varnish  is  sold  by  every  dealer,  but  may  at  need  be 
made  thus : 

Seed  lac  1  pound 

Methylated  spirit 1  quart 

Keep  some  days  in  a  warm  place,  shaking  occasionally.     After 
four  days  decant  and  filter. 

To  apply  varnish :  Heat  the  plate  to  blood  heat,  apply  the 
varnish  after  the  manner  of  collodion,  drain  well,  removing 
the  last  drip  by  resting  lower  part  of  the  plate  on  bibulous 
(filter  or  blotting)  paper.  Then  heat  again  till  the  back  of 
hand  cannot  bear  it.  The  varnish  must  not  be  allowed  to  dry 
cold. 

For  certain  purposes  negatives  in  black  and  white  are  re- 


THE    PROCESSES    OF    PUKE    PHOTOGRAPHY.  45 

quired.     For  such  purposes — copies  of  plans,  line  engravings, 
etc — the  negative  may  be  intensified  thus  : 

Mercuric  chloride 1  part 

Water..    20  parts 

Acidified  with  hydrochloric  acid. 

Immerse  in  this  till  the  image  is  almost,  or  quite,  white. 
Then  plunge,  after  thorough  washing,  into : 

Liquor  ammonia,  fort 1  part 

Water 20  parts 

The  image  will  now  turn  densely  black.     Wash  thoroughly. 
Dry,  and  varnish  as  before. 


CHAPTER  VII. 
A  DRY  COLLODION   PROCESS. 

DRY  collodion  plates  are  very  rarely,  if  ever,  now  used  for 
making  negatives,  but,  as  the  process  naturally  follows  the  wet 
collodion  process,  we  propose  to  insert  here  a  dry  collodion 
process,  which  we  have  used  extensively  and  successfully  for 
lantern-slides,  and  which  may  be  used,  if  desired,  for  negative- 
making.  The  formula  is  mainly  due  to  Mr.  "W.  B.  Bolton. 

Dry  collodion  emulsion  is  called  "washed"  or  "  unwashed," 
according  to  the  stage  at  which  it  is  washed,  for  washed  it 
always  is,  at  one  stage  or  another.  Instead  of  using  a  bath  of 
silver  nitrate  solution,  and  immersing  a  coated  plate  therein, 
we  add  the  silver  nitrate  to  the  liquid  salted  collodion,  thereby 
producing  an  "  emulsion  "  of  silver  haloids  in  collodion,  and 
that  emulsion,  sensitive  to  light,  we  pour  on  plates  which  we 
thereafter  dry.  But  in  the  process  of  "double  decomposition," 
by  which  the  sensitive  salts  are  formed,  there  are  formed  other 
compounds,  or  "  bye-products,"  which,  if  left  to  dry  on  the 
emulsion,  or  on  the  film,  would  crystallize,  and  spoil  all  our 
plates.  In  the  "  washed  "  emulsion  process  these  bye-products 
are  washed  out  of  the  bulk  of  emulsion  before  the  plates  are 
coated.  In  the  "  unwashed  "  emulsion  process  the  bye-products 
are  washed  out  of  the  film  of  each  plate  after  it  is  coated. 

UNWASHED  COLLODION  EMULSION  PROCESS. 
The  zinc  bromide  must  be  dry,  or  dried  by  heat  on  a  clean 
surface'.    The  pyroxylin  e  is  that  made  at,  and  known  as,  "  high 
temperature." 


Sulphuric  ether,   .720  .....................   3J4  fluid  ounces. 

Alcohol,   .820  ...........................  .  2      fluid  ounces. 

Pyroxyline,  (H.T.)  ......................  36      grains. 

Zinc  bromide  ............................  59      grains. 

Mix  in  this  order,  and  let  stand  one  day,  at  least,  to  settle. 


THE    PROCESSES    OF    PUKE   PHOTOGRAPHY.  47 

After  the  above  are  fully  dissolved  and  any  precipitate 
settled,  dissolve  ninety  grains  silver  nitrate  in  a  test-tube,  with 
forty-five  minims  of  distilled  water,  boiling.  Boil,  in  another 
test-tube,  six  drams  of  alcohol  .820,  and  while  both  test-tubes 
are  at  the  boil,  pour  about  four  drams  of  the  alcohol  into  the 
silver  solution,  reserving  two  drams  for  future  use.  Now  take 
the  two  test-tubes  and  the  bromized  collodion  into  the  dark- 
room (yellow  light  will  do)  and  little  by  little  pour  the  hot 
alcoholic-aqueous  silver  solution  into  the  collodion,  shaking  the 
latter  violently  after  each  addition  of  silver.  After  all  the 
silver  solution  is  into  the  collodion,  use  the  two  drams  of  alco- 
hol in  reserve  to  rinse  out  the  silver  which  will  be  crystallized, 
probably,  in  the  test-tube,  and  add  that  to  the  collodion. 
Shake  vigorously  for  a  minute  or  two.  We  have  now  formed 
a  collodio  emulsion  of  silver  bromide,  which  is  left  to  "  ripen" 
for-  several  days.  When  fully  "  ripened,"  the  emulsion  is 
filtered  through  pure  cotton  wool,  glass  wool,  or  swan's-down 
calico,  and  plates  are  coated  with  it.  For  this  process,  the 
plates  should  be  carefully  cleaned,  and  they  should  have  a  sub- 
stratum of  albumen,  or  an  "edging"  of  india-rubber  dissolved 
in  pure  benzole.  The  albumen  solution  is  made  by  switching 
the  white  of  an  egg  with  forty  ounces  of  water,  adding  liquor 
ammonia  till  the  smell  of  ammonia  is  distinctly  perceptible, 
letting  stand,  and  filtering  most  carefully.  This  improves  by 
keeping,  but  the  ammonia  smell  must  be  kept  up.  The  clean 
but  wet  glass  plate  is  flowed  twice  with  the  albumen,  then 
dried. 

The  plate  coated  with  collodion  emulsion  is  left  till  the  col- 
lodion sets,  when  it  is  plunged  into  distilled  water,  after  which 
it  may  be  washed  in  ordinarily  pure  water  till  greasiness  dis- 
appears ;  after  this  it  is  placed  for  about  a  minute  in  one  of 
the  following  solutions : 

1.  Coffee  (ground) 2  ounces 

Boiling  water 10  ounces 

carefully  filtered. 

2.  Bitter  beer 10  ounces 

Pyrogallol 10  grains 

filtered. 


48  THE    PROCESSES    OF    PUKE    PHOTOGRAPHY. 

After  No.  2  the  plate  is  to  be  washed  before  drying,  but  not 
after  iNo.  1.  Drying  may  be  accelerated  by  gentle  heat. 

Washed  Collodion  Emulsion. — Process  of  sensitizing  is 
very  similar  to  that  given  for  unwashed  emulsion. 

Ether,  .720 3±  ounces 

Alcohol,  .820 2    ounces 

Pyroxyline 48  grains 

Zinc  bromide 72  grains 

To  sensitize  use,  this  time,  silver  nitrate  1 20  grains.  The 
ripening  is  allowed  to  proceed  as  before,  and  thereafter  the 
emulsion  is  poured  out  into  a  large,  flat,  clean  dish  in  the  dark- 
room, and  allowed  to  set  thoroughly.  As  a  skin  forms  on  the 
top,  it  is  broken  with  a  clean  bone,  horn,  ivory  or  silver  instru- 
ment, so  that  it  may  "  set,"  by  evaporation  of  the  solvents,  to 
the  very  bottom.  The  emulsion  is  then  cut  or  broken  or  torn 
into  very  small  shreds,  and  washed  in  running  water  for  several 
hours.  The  "  pellicle,"  or  dry  emulsion,  after  being  broken 
up,  may  be  put  into  a  tea-pot,  a  piece  of  muslin  tied  over  the 
top,  and  a  stream  of  water  directed  down  the  spout  for  a  night. 
The  pellicle  is  next  thoroughly  dried,  first,  by  squeezing,  next, 
by  submersion  under  alcohol  for  an  hour  or  two.  It  is  then 
dissolved  in  ether  and  alcohol,  thus : 

Pellicle  20  grains 

Ether 4  drams 

Alcohol 4  drams 

The  plates  are  coated  with  this,  and  require  only  to  be  dried. 

Development. — For  lantern-slides  the  developers  we  prefer 
will  be  found  under  the  heading  appropriate,  page  176.  We 
here  briefly  state  a  method  suitable  for  plates  made  by  this 
process,  and  exposed  upon  landscape  subjects.  The  required 
exposure,  we  may  say,  is  very  long  compared  with  other  nega- 
tive processes  in  common  use. 

Flow  the  film  with 

Methylated  spirit 1  part 

Water I  part 

for  half  a  minute.     Wash  under  the  tap. 


THE  PROCESSES  OF  PURE  PHOTOGRAPHY.  49 

COL.  STUART  WORTLEY'S  DEVELOPER. 

1.  Pyrogallol 96  grains 

Alcohol 1  ounce 

2.  Potassic  bromide  120  grains 

Water 1  ounce 

3.  Liquor  ammonia 6  minims 

Water 1  ounce 

Developer  consists  of 

No.  1 6  minims 

No.  2 3  minims 

No.  3 . .  3  drams 

mixed. 

This  is  poured  upon  the  plate,  or  into  a  flat  dish  in  which 
the  plate  is  placed,  and  after  a  short  time  the  image  will  begin 
slowly  to  appear  and  gradually  to  gain  strength,  Develop- 
ment does  not  progress  nearly  so  quickly  as  with  wet  collo- 
dion. 

Re-development,  fixing,  intensification,  and  varnishing  may 
be  conducted  exactly  as  in  the  wet  process;  '"pyro"  being 
preferable  to  iron  for  "  strengthening  "  processes. 

As  a  rule,  a  dry  collodion  plate  for  landscape  work,  the  film 
being  very  thin  and  transparent,  requires  "  backing."  This  is 
done  by  painting  the  back  of  the  plate  with  a  pigment  of  the 
following  nature  (Abney): 

Powdered  sienna,  burnt 1  ounce 

Gum  arabic 1  ounce 

Glycerine 2  drams 

Water 10  ounces. 

This  is  to  be  removed  before  development,  a  sponge  being 
used. 

The  ferrous  oxalate  developer  gives  fine  results  with  dry 
collodion  plates  (see  page  91.) 


CHAPTER  VIII. 
GELATINE    EMULSION    PROCESSES— PRELIMINARY. 

WE  cheerfully  acknowledge,  and  proudly  assert,  that  in  the 
markets  of  every  civilized  country,  plates  prepared  for  photo- 
graphic purposes,  with  gelatine  emulsion,  are  found,  excellent 
in  their  qualities,  and  suitable  for  every  purpose  for  which 
they  may  be  intended.  We  do  not  expect  that  any  person  mak- 
ing emulsion  on  a  small  scale,  or  with  limited  appliances,  will 
produce  plates  of  such  even  perfection  as  those  of  professional 
plate-makers;  and  we  are  pretty  confident  that  the  amateur 
plate-maker  will  not  save  any  money  by  his  plate-making.  But 
we  urge  upon  every  one  who  wishes  to  work  with  intelligent 
comprehension  of  what  he  is  doing,  and  every  one  who  has  the 
ambition  to  further  photographic  knowledge,  by  his  own  efforts 
to  acquire  a  perfect  knowledge  of,  and  facility  in,  the  produc- 
tion of  gelatine  emulsion,  and  the  preparation  of  plates,  or 
paper,  therewith.  No  treatise  on  modern  photography  would, 
in  our  opinion,  be  worthy  the  name,  unless  it  showed  evidence 
of  an  attempt,  at  least,  to  initiate  its  readers  into  this,  the  most 
important  photographic  process  of  the  present  day.  Our 
modest  directions  shall  be  given,  to  the  best  of  our  ability,  in 
such  a  way  that  any  intelligent  person  following  them,  shall 
be  able  to  produce  a  good  emulsion,  and  with  a  little  practice, 
to  prepare  good  plates ;  at  any  rate,  so  that  any  person  reading 
them  with  moderate  attention  shall  grasp  the  facts  guiding  our 
practice,.and  the  conditions  necessary  to  ensure  success.  The 
change  of  "  vehicle  "  from  collodion  to  gelatine  carries  in  its 
train  more  important  considerations  than  might,  at  first  sight, 
be  expected.  In  a  collodion  emulsion  the  collodion  is  practi- 
cally a  purely  mechanical  menstruum,  in  a  gelatine  emulsion 
the  part  played  by  the  gelatine  is  more,  by  far,  than  mechani- 


THE    PROCESSES    OF    PUKE    PHOTOGRAPHY.  51 

cal.  Many  of  our  most  mysterious  and  aggravating  failures 
arise  from  this  fact.  Again,  one  property  of  gelatine  is,  that 
it  permits  of  a  silver  haloid  being  formed  in  it  in  a  state  of 
very  fine  division,  and  of  that  fine  st.ite  of  division  being  car- 
ried through  various  stages  to  a  much  coarser  state ;  as  a  num- 
ber of  "  marbles  "  lying  together  expose  to  light  a  much  larger 
amount  of  surface  than  a  much  larger  number  of  "  shot  drops," 
so  a  coarse-grained  deposit  of  silver  haloid  is  more  affected  by 
light  than  a  fine-grained  one.  Moreover,  the  gelatine  is  a  more 
powerful  halogen  absorbent  than  collodion,  and  so  conduces  to 
greater  sensitiveness;  and  lastly,  the  gelatine,  apparently  pro- 
tecting more  strongly  the  silver  haloid  molecules,  permits  of  a 
much  more  vigorous  reducing  agent  being  applied  in  de- 
velopment. 

The  haloid  chiefly  used  in  gelatine  emulsions,  for  negative 
work,  is  silver  bromide,  and  as  its  general  sensitiveness,  as  well 
las  its  special  sensitiveness  to  the  less  refrangible  rays,  is  greater 
than  that  of  iodide,  we  have  to  take  greater  precautions  as  to 
safety  of  our  light  with  gelatine  bromide  emulsion  than  with 
either  collodio-bromide  or  the  iodide  of  the  wet  collodion 
process.  In  fact,  if  we  propose  to  make  gelatine  bromide 
emulsion  of  any  suitable  degree  of  sensitiveness,  we  should  use 
for  illumination  either  ruby  and  yellow  glasses,  or  several 
layers  of  orange  paper,  or  other  fabric. 

Certain  apparatus  must  be  provided  before  any  other  step 
should  be  taken  towards  emulsion  making. 

A  drying-press  will  be  required  for  drying  the  plates  after 
they  are  coated,  and  it  must  be  noted  that  aqueous  solution 
of  gelatine  is  by  no  means  easily  or  speedily  dried.  The  press 
must,  of  course,  be  absolutely  light-tight,  and  the  drying  must 
depend  on  a  constant  current  of  cool,  dry  air  rather  than  on 
any  system  depending  on  heat.  We  illustrate  by  a  cut,  Fig. 
1 6,  a  press,  the  principle  of  which  may  serve  to  guide  others 
who  wish  to  construct  a  drying-press. 

Drying-closet,  designed  by  one  of  the  writers  (see  Pho- 
tographic Times,  1888,  pp.  133-135),  6x6  feet  by  9  feet 
high  ;  cross  section  of  air-passage  one  square  foot  area.  The 
air  is  drawn  from  a  veranda  and  heated  by  an  oil  stove.  No 


52 


THE    PROCESSES    OF    PURE    PHOTOGRAPHY. 


burnt  air  comes  in  contact  with  the  plates,  the  heat  being  used 
solely  to  create  draught.  (For  full  description,  see  article 
cit.  sup.) 


FIG  16. 


Receptacles,  too  small  to  be  called  "presses,"  are  sometimes 
used  on  a  small  scale ;  these  are  described  and  figured  in  many 


THE    PROCESSES    OF   PURE   PHOTOGRAPHY.  53 

journals  and  books  ;  one  designed  by  Mr.  "W.  England  is,  per- 
haps, as  good  as  any. 

A  drying-room  will  be  found  far  superior  to  smaller  recep- 
tacles. If  any  apartment  provided  with  thorough  ventilation 
and  means  for  entirely  excluding  every  speck  of  light  can  be 
found,  plates  will  dry  in  such  a  room,  even  if  it  be  only  ten  or 
twelve  feet  square,  much  more  quickly  than  in  any  box,  or 
even  cupboard.  Dry  air,  in  a  constant  and  vigorous  current,  is 
the  required  agent  for  desiccation.  Heated  air  may  be  used  to 
create  a  draught,  but  products  of  combustion,  as  from  burnt 
gas,  oil,  or  coal,  must  on  no  account  be  allowed  to  enter  the 
drying  receptacle.  While  drying,  the  plates  are  usually  placed 
on  drying-racks,  or  they  may  be  made  to  lean  against  upright 
spars,  with  the  film  turned  away  from  any  direction  whence 
dust  might  come.  Plenty  of  room,  as  well  as  plenty  of  air- 
current,  is  required. 

Leveling  Slab. — As  the  plates  are  coated  with  a  warm  ^nd 
liquid  solution  of  gelatine,  which  sets  in  a  firmer  jelly  when 
cold,  and  as  the  plates  must  have  an  even  film  of  the  emulsion, 
it  is  necessary  to  have  a  level  table  whereon  to  lay  the  plates 
after  they  are  coated  until  the  gelatine  sets.  And  as  it  is  ad- 
vantageous to  cause  the  gelatine  to  set  as  rapidly  as  possible, 
this  level  table  should  be  cold.  A  slab  of  thick  plate  glass, 
slate,  or  marble  is  generally  used,  and  it  is  necessary  to  have 
means  of  leveling  the  slab.  One  of  the  writers  uses  the  large, 
thick,  marble  slab  of  a  wash-hand-stand,  leveled  with  screws 
from  below.  As  emulsion  usually  gets  accidentally  upon  the 
back  of  the  plate,  and  causes  the  plate  not  only  to  be  unlevel, 
but  to  stick  to  the  slab,  it  is  well  to  stretch  strings  or  piano 
wires  tightly  across  the  top  of  the  slab. 

Apparatus  for  Mixing,  Cooking,  and  Washing  the  Emul- 
sion.— For  mixing  the  emulsion  any  vessel  may  be  used  that 
will  stand  heat  and  will  not  in  any  way  chemically  affect 
the  emulsion.  Glass  beakers  must  be  very  carefully  handled, 
and  vitrified  stoneware  jars  are  preferable  ;  glazed  earthen- 
ware must  be  avoided.  We  figure  an  article,  known  as  a 
"  shut-over  jar,"  which  we  find  admirably  suited  for  emulsion 
operations ;  the  price  is  trifling,  and  the  jars  are  practically 


54  THE   PROCESSES   OF   PUKE   PHOTOGRAPHY. 

light-tight,  though  we  do  not  unnecessarily  expose  them  to 
light.  Flasks  or  bottles  should  be  of  glass,  so  that  we  can  tell 
whether  they  are  clean  or  not. 


FIG.  17. 

Some  appliance  is  needed  in  order,  at  a  certain  stage,  to 
break  up  the  emulsion  which  lias  set  into  a  jelly,  and  this 
appliance  must,  if  metal,  be  of  "  noble  "  metal — silver,  gold, 
platinum,  etc.;  or  it  may  be  of  ivory,  ebonite,  etc.  Frequently 
the*  jelly  is  forced  through  a  piece  of  coarse  canvas,  which 
must  be  thoroughly  clean.  Sometimes  the  jelly  is  forced 
through  a  silver  wire  mesh  by  means  of  a  plunger  working  in 
a  cylinder. 

For  washing  the  emulsion  a  hair  sieve  will  be  handy,  as 
described  later,  or  a  tea-pot  may  be  utilized,  as  also  mentioned 
later.  Mr.  Henderson,  of  London,  provides  the  most  satisfac- 
tory emulsion  washer  we  have  seen,  but  we  have  not  space  to 
describe  or  illustrate  it  here.  An  operation  superior,  in  our 
estimation,  to  washing  is  that  of  "centrifugal  separation," 
remarks  on  which  we  must  also  reserve. 


CHAPTER    IX. 

GELATINE-BROMIDE  EMULSION. 
PART  I. 

To  Make  a  Slow  Gelatino-Chloro-Bromide  Emulsion,  suit- 
able for  subjects  with  which  shortness  of  exposure  is  no  object. 
The  exposure  for  this  emulsion  will  be  about  the  same  as  that 
for  an  ordinary  "  wet-plate." 

a.  Gelatine — Nelson's  No.  1 60  grains 

Soak  in 

Water 6  ounces 

for  a  few  minutes.     Add 

Potassic  bromide 275  grains 

Potassic  chloride 40  grains 

Ten  per  cent,  dilution  of  strong  hydrochloric  acid 

i  n  water 25  minims 

b.  Silver  nitrate 400  grains 

Water 6  ounces 

Remarks  on  the  above,  which  will  apply  throughout  our 
chapters  on  emulsion-making.  Potassic  bromide  is  frequently 
found  alkaline.  Such  must  at  once  be  rejected.  Slighf  acidity 
no  harm.  The  same  applies  to  potassic  chloride,  The  amount 
of  argentic  chloride  resulting  from  the  above  quantity  of 
potassic  chloride  is  very  small,  but  the  color  of  the  image 
seems  to  be  improved  by  the  presence  of  the  chloride.  Hence 
we  recommend  this  emulsion  for  lantern-slides  (see  Chapter 
XXX.) 

Kelson's  No.  1  gelatine  is  generally  used  for  the  emulsifica- 
tion  on  account  of  its  purity,  but  it  is  not,  on  account  of  its 
softness,  so  well  adapted  for  forming  the  bulk  of  the  gelatine 
in  the  finished  emulsion,  (vide  "  <?.") 


56  THE    PROCESSES    OF   PUKE    PHOTOGRAPHY. 

The  water  may  be  good  tap-water,  but  we  prefer  distilled. 
The  silver  nitrate  is  obtainable  of  the  utmost  purity  at  a 
proper  price,  and  from  a  proper  source. 

The  ingredients  of  a  being  all  mixed,  heat  is  applied  till  all 
are  melted. 

It  is  well  now  to  prepare  c. 

f.  "  Hard  "  gelatine,  as  Heinrich's,  or  Nelson's  "  X 

Opaque  " 600  grains 

Water  to  cover  it. 

This  gelatine  should  be  previously  .washed  once  or  twice  in 
distilled  water  to  which  a  drop  or  two  of  ammonia  is  added  ; 
but  there  is  to  be  no  ammonia  in  c  when  actually  used. 

Emulsification. — Put  a  into  a  large  vessel,  capable  of  hold- 
ing at  least  five  times  the  measure  of  a.  Heat  both  a  and  b 
to  150  deg.  Fahr.,  and  take  them  into  the  dark-room,  which, 
from  this  stage,  must  be  "safely"  lighted  (see  previous  re- 
marks.) Shake  a  vigorously  in  its  bottle  till  it  froths,  and 
pour  into  it  a  small  quantity  of  Z>.  Shake  vigorously,  and  go 
on,  little  by  little,  pouring  I  into  a,  shaking  vigorously  each 
time,  till  the  whole  of  b  is  mixed  into  a,  and  a  is  in  a  complete 
state  of  froth.  Kinse  out  b  with  a  small  quantity  of  water  ; 
pour  into  a,  and  shake  for  two  or  three  minutes,  a  will  now 
be  a  creamy  emulsion  of  gelatine  and  silver  chloro-bromide. 
A  cover  is  now  placed  on  the  vessel  containing  a  and  b  mixed, 
or,  failing  a  cover,  the  emulsion  is  by  other  means  kept  warm 
for  about  an  hour,  being  well  stirred  several  times  during  that 
time.  Then  <?,  being  melted  by  heat,  gently  applied,  the 
emulsion  is  mixed  with  it,  and  the  two  thoroughly  incorporated 
by  stirring  vigorously.  The  whole  should  be  heated  to  about 
140  deg.  Fahr.,  and  is  then  placed  aside  to  cool  and  to  "  set." 
In  very  hot  weather  it  may  be  reluctant  to  set,  or  it  may 
refuse,  in  extreme  cases  of  heat,  to  set  at  all.  In  this  case 
cold  or  even  iced-water  may  be  required  to  make  it  set.  The 
jar  containing  the  now  complete  but  unwashed  emulsion,  may 
be  placed  in  iced-water  till  the  emulsion  sets  into  a  stiff  jelly. 

Emulsification  is  conveniently  performed  sometimes  in  a 
manner  suggested  by  Mr.  T.  S.  Davis.  The  silver  nitrate  of 


HIE    PROCESSES    OF    PURE    PHOTOGRAPHY.  57 

b  is  added  inf  the  dry  crystallized  state  to  a,  the  water  of  b 
being  added  at  first  to  a.  In  this  case,  the  crystals,  of  b 
are  added  all  at  once  to  a,  and  vigorous  shaking  goes  on  till 
the  crystals  are  no  longer  heard  clinking  in  the  vessel  con- 
taining a. 

Washing  is  necessary,  as  we  have  hinted,  to  eliminate  the 
bye-product  of  decomposition,  which,  in  this  case,  is  potassic 
nitrate ;  this  salt,  if  left  in  the  emulsion,  would  probably  crys- 
tallize on  the  film  ;  but  luckily  it  is  soluble  in  water,  while  our 
sensitive  silver  haloids  are  not  soluble  in  water.  We,  there- 
fore, only  require  to  let  water  reach  the  soluble  nitrate  in  order 
to  dissolve  it,  but  the  crux  is  to  ensure  the  water  reaching  the 
nitrate  through  the  mass  of  repellant  gelatine.  Our  plan  is  to 
break  or  cut  up  the  emulsion  jelly  into  very  fine  fragments  or 
shreds,  and  to  allow  water  to  percolate  for  a  considerable  time 
through  and  among  these  fragments.  There  are  several  meth- 
ods of  breaking  up  the  jelly.  It  may  be  removed  from  its  jar 
with  a  silver  spoon  or  spatula,  or  a  clean  ivory,  bone,  or  ebonite 
paper-cutter,  and  placed  on  a  piece  of  canvas  with  a  large  mesh. 
The  canvas  is  then  gathered  up  at  the  corners,  so  as  to  form  a 
bag,  the  bottom  of  which  is  held  under  water,  while  the  top  is 
twisted  up  tighter  and  tighter,  till  the  jelly  oozes  out  into  the 
water,  in  long,  fine  threads.  We  frankly  own  this  operation 
is  not  to  our  taste.  We  prefer  to  cut  the  jelly  into  small  cubes, 
place  these  in  a  cylinder  of  glass  or  vulcanite,  having  at  its  end 
a  mesh  of  silver  wire,  into  the  other  end  fits  nicely  a  plunger, 
which  we  force  down  upon  the  jelly,  till  the  latter  oozes  out, 
as  before,  in  long  threads,  into  water  kept  (or  naturally)  cold. 
Either  of  these  operations  may,  with  advantage,  be  repeated 
later,  to  insure  more  complete  washing. 

The  shreds  of  jelly  may  be  received  under  water  in  a  hair- 
sieve,  which  is  lifted  occasionally  during  the  washing.  The 
sieve  may  sit  in  an  ordinary  china  basin.  If  the  washing  be 
performed  with  running  water,  and  the  sieve  be  occasionally 
lifted  and  the  basin  emptied,  the  washing  should  be  complete 
in  an  hour.  The  threads  may  be  received  in  an  earthen  tea- 
pot, a  piece  of  muslin  tied  over  the  top,  and  water  run  in 
through  the  spout  for  an  hour.  For  years  we  used  the  teapot 


58  THE   PROCESSES   OF   PUKE   PHOTOGRAPHY. 

for  washing,  and  found  it  answer  well.  The  water  should  not 
be  of  higher  temperature  than  65  deg.  Fahr. ;  lower  is  prefer- 
able. 

The  threads,  being  washed,  may  be  gathered  into  a  muslin 
bag,  and  squeezed,  to  remove  superfluous  moisture.  Or  the  bag, 
being  of  ample  size,  may  be  whirled  round  the  operator's  head 
energetically.  In  any  case,  not  much  water  must  remain,  or 
there  will  be  a  danger  of  the  finally-melted  emulsion  being  too 
thin.  Finally,  add  to  the  emulsion,  in  a  jar,  one  and  a  half 
ounce  of  the  following  : 

Alcohol 1  pint 

Thymol 100  grains 

The  emulsion  now  only  requires  to  be  melted  by  heat,  and 
filtered  through  swan's  down  calico,  or  some  similar  medium, 
when  it  is  ready  for  coating  plates. 

A  Rapid  Gelatine  Bromide  Emulsion  ~by  the  Boiling  Pro- 
cess.— In  this  case  much  greater  sensitiveness  is  obtained  by 
boiling  the  emulsion  in  presence  of  only  a  small  proportion  of 
the  gelatine  used  in  the  last  process  for  emulsification.  Gela- 
tine is  decomposed  by  boiling,  and  loses  its  power  of  setting, 
so  that  the  less  we  can  use  during  the  boiling  the  better.  More- 
over, boiling  in  the  presence  of  a  chloride  is  apt  to  produce 
fog,  and  further,  the  color  of  the  image,  in  a  process  used 
solely  as  this  is,  for  the  production  of  negatives,  is  of  no  mo- 
ment. The  addition  of  an  iodide  is  found  to  give  greater 
clearness  to  the  plates  prepared  with  the  emulsion,  so  in  this 
process  we  replace  the  chloride  of  last  process  by  an  iodide. 

a.  Potassic  bromide 320  grains 

Potassic  iodide 20  grains 

Gelatine— Nelson's  No.  1 60  grains 

Water 6  ounces 

Mixed  as  before,  and  slightly  acidified  with  hydrochloric 
acid  as  before. 

b.  Silver  nitrate 400  grains 

Water 6  ounces 

As  before. 

f.  Gelatine— hard,  as  before 500  grains 

Water  to  cover  it. 

Washed  as  before. 


THE    PROCESSES    OF    PURE    PHOTOGRAPHY.  59 

If  a  be  alkaline,  fog  will  supervene.  If  too  acid,  long  boil- 
ing will  be  required  to  produce  great  sensitiveness, 

Emulsify  precisely  as  before,  but  after  emulsification,  in- 
stead of  placing  the  emulsion  aside  to  cool  gradually,  place  the 
vessel  containing  it  in  a  saucepan  of  hot  water.  If  emulsifi- 
cation was  conducted  in  a  glass  flask,  the  emulsion  should  at 
this  stage  be  put  into  a  "  shut-over  jar"  (vide  supra),  and  the 
jar,  with  its  cover  on,  put  into  the  saucepan,  or  other  covered 
vessel  of  water ;  the  water  is  then  to  be  boiled  for  a  certain 
time,  the  jar  standing  in  it.  It  is  impossible  to  say  how  long 
the  emulsion  is  to  be  "  cooked "  in  this  way.  The  only  way 
to  tell  when  to  stop  boiling  is  by  examining  the  color  of  the 
emulsion,  spread  out  in  a  thin,  watery  film,  on  a  piece  of  glass. 

Immediately  after  emulsification  the  emulsion  should  be 
stirred  with  a  slip  of  glass,  and  the  glass  examined  by  aid  of  a 
flame  of  gas,  or  an  oil  lamp.  (Of  course  the  emulsion  in  the 
jar  must  be  kept  covered  if  the  examination  take  place  in  the 
dark-room).  The  emulsion  will  show  a  dark  orange,  or  even 
ruby  color  at  first,  but  as  boiling  progresses,  the  color  will 
gradually  become  more  blue,  until,  at  last,  it  is  distinctly 
blue.  The  emulsion  at  this  stage  has  acquired  fair  sensi- 
tiveness. If  we  desire  more  than  this,  we  may  go  on 
boiling  as  long  again  as  was  required  first  to  obtain  the 
blue  tint.  But  when  the  boiling  is  continued  long  after 
the  blue  tint  is  reached,  the  dangers  of  the  process  come  in, 
and  extravagant  boiling  will  result  in  granularity  and  utter 
fog.  The  microscopic  test  is  also  valuable  as  an  aid  to  the 
color  test.  If  the  emulsion  on  the  strip  of  glass  used  for 
stirring  (which  should  be  pretty  frequent,  at  intervals  of  say 
ten  minutes)  be  occasionally  examined  under  the  microscope, 
the  same  power  being  always  used,  it  will  be  noticed  that  as 
boiling  is  continued,  the  "grain"  of  the  emulsion  becomes 
coarser  and  coarser  and  practice  will  enable  the  worker  to  use 
the  microscope  as  a  valuable  aid  to  the  color  test. 

After  the  boiling  is  judged  to  be  sufficient,  the  emulsion  is 
cooled  to  140  deg  Fahr.,  added  to  c,  and  operations  are  the 
game  as  those  given  for  the  slow  emulsion. 


CHAPTER  X. 

GELATINE-BROMIDE     EMULSION     BY    THE    AMMO- 

NIO-NITRATE  PROCESS,  AND  PRECIPITATION 

BY  ALCOHOL.— CENTRIFUGAL  SEPARATION. 

IN  the  process  known  as  the  ammonio-nitrate  process,  boiling 
of  the  emulsion  is  dispensed  with,  and  in  place  of  the  boiling 
is  substituted  a  system  of  keeping  the  emulsion  at  a  medium 
temperature  for  a  certain  time,  but  in  a  condition  of  strong 
alkalinity.  As  a  general  rule,  it  may  be  stated  that  a  high 
degree  of  sensitiveness  is  more  easily  obtained,  and  the  results 
are  more  equal,  by  the  ammonia  than  by  the  boiling  process ; 
while,  on  the  other  hand,  the  opinion  is  common,  if  not  univer- 
sal, that  the  general  quality  of  a  boiled  emulsion  is  superior  to 
that  of  an  ammonia  emulsion. 

The  defect  most  frequently  attributed  to  emulsion  made  by 
the  ammonio-nitrate  process,  is  a  propensity  to  "  green  fog,"  a 
disease  not  easy  to  describe,  but  easy  to  diagnose  from  the 
name  when  once  it  is  seen.  The  formula  we  now  give  will, 
we  venture  to  state,  give  an  emulsion  of  the  highest  sensitive- 
ness when  required,  and  will  none  the  less  be  free  from  fog, 
and  will  stand  without  fogging  an  unusual  amount  of  "  forcing  " 
by  alkali  in  development.  The  system,  as  will  be  seen,  may 
be  described  as  a  compromise  between  the  ammonio-nitrate 
process,  where  the  silver  is  entirely  "converted,"  and  the 
boiling  process,  wherein  the  gelatine  used  in  cooking  is  practi- 
cally destroyed,  and,  so  far  as  possible,  rejected. 

A.  Ammonium  bromide 270  grains 

Potassic  iodide 20  grains 

Gelatine— Nelson's  No.  1 60  grains 

Water 10  ounces 

B.  Silver  nitrate  crystals 250  grains 


THE    PROCESSES    OF    PURE   PHOTOGRAPHY.  61 

D.   Silver  nitrate 150  grains 

Water \\  ounce 

C.  Gelatine — hard,  as  in  last  chapter 400  grains 

C  is  "  converted "  into  ammonio-nitrate  thus :  The  silver 
nitrate  being  fully  dissolved,  strong  liquor  ammonia  is  added 
to  the  solution  slowly,  a  little  at  a  time  at  first,  and  latterly 
drop  by  drop.  At  the  first  additions  of  ammonia,  a  dark  pre- 
cipitate is  formed,  but  as  the  additions  go  on  the  precipitate  at 
last  is  re-dissolved  and  disappears.  The  vessel  should  be  well 
shaken  towards  the  end,  or  its  contents  well  stirred ;  and  in 
order  that  the  progress  may  be  seen,  glass  should  be  the 
material  for  the  vessel.  As  soon  as  the  precipitate  is  entirely 
re-dissolved  the  operation  is  complete. 

D  requires  no  remark  further  than  that  the  proportion  of 
gelatine  finally  allotted  to  an  emulsion  seems  to  make  very 
little  difference  to  its  qualities.  A  very  large  quantity  of 
gelatine  slows  an  emulsion  slightly,  but  allows  of  more 
"forcing"  in  development. 

To  Emulsify. — Raise  A  to  a  temperature  varying  from  100 
to  160  deg.  Fahr.,  according  to  the  sensitiveness  required  in 
the  final  emulsion.  The  higher  the  temperature  the  more  sen- 
sitive ought  to  be  the  emulsion.  Even  180  deg.  Fahr.  is  per- 
missible, and  will  give  an  exceedingly  sensitive  emulsion,  but 
there  is  a  danger  of  fog,  and,  probably,  the  plates  will  require 
great  care  in  working,  even  if  actual  and  irremediable  fog  be 
avoided.  A  temperature  of  100  deg.  Fahr.  at  this  stage  will 
give  quite  a  slow  emulsion,  probably ;  160  deg.  Fahr.  will  give 
a  plate  as  rapid  as  most  so-called  "  extra-rapid  "  plates  in  the 
market.  To  insure  thorough  solution  and  mixing  of  the  in- 
gredients of  A,  the  temperature  should  be  raised  to  150  deg. 
Fahr.,  anyhow  ;  and  if  100  or  120  deg.  Fahr.  be  the  tempera- 
ture desired  for  emulsification,  the  solution  may  be  allowed  to 
cool  to  the  desired  point.  As  it  is  evident  that  temperature  is 
the  crucial  point  in  this  operation  ;  as,  clearly,  a  small  bulk  of 
solution  will  cool  rnqre  rapidly  than  a  large  bulk,  and  as  regu- 
larity of  result  is  desirable,  a  large  quantity  of  water  should  be 
heated  to  the  desired  temperature  in  a  covered  saucepan — a 
gallon  or  two,  but  always  the  same  quantity — and  in  this  the 


62  THE   PROCESSES    OF   PUKE    PHOTOGRAPHY. 

jar  containing  A  is  to  be  immersed  till  A  takes  the  desired 
temperature.  B  is  now  added,  with  shaking,  to  A,  as  in  last 
chapter.  Next,  C  is  added,  cold,  little  by  little,  with  vigorous 
stirring  after  each  addition.  Of  course,  the  emulsifieation  must 
be  done  in  the  dark-room,  and  with  special  precautions  as  to 
light,  for  this  emulsion  is  pretty  sensitive,  from  its  very  forma- 
tion. After  the  whole  of  C  is  added,  the  entire  bulk  must  get 
a  vigorous,  or  even  violent,  shaking,  for  two  or  three  minutes, 
and  is  then  covered  and  put  in  the  covered  saucepan  for  two 
hours.  Beyond  two  hours  it  is  dangerous  to  go,  and  after  that 
time  it  is  well  to  help  the  cooling,  by  placing  the  jar  containing 
the  emulsion  in  cold  water.  When  the  temperature  has  fallen  to 
70  deg.  Fahr.,  the  gelatine,  D,  is  placed,  dry,  in  the  emulsion ; 
or  D  may  be  washed,  if  it  is  a  greasy  or  otherwise  impure 
sample,  with  water  containing  a  trace  of  ammonia ;  this  wash- 
ing should  be  done  quickly,  and  the  water  squeezed  entirely 
out  of  the  gelatine  before  it  is  put  into  the  emulsion.  D  hav- 
ing been  allowed  to  soak  for  about  half  an  hour  in  the  emul- 
sion, the  heat  is  slowly  raised  to  not  over  110  deg.  Fahr., 
preferably  100  deg.  Fahr.,  when  the  whole  of  the  gelatine 
ought  to  be  in  a  liquid  state.  Stir  well,  'cool  quickly,  and 
allow  to  set  in  a  stiff  jelly.  This  may  be  washed,  as  in  last 
chapter,  or  may  be  precipitated  for  washing. 

Precipitation  by  Alcohol. — Silver  bromide  is  insoluble  in 
alcohol  as  in  water ;  gelatine  is  soluble  in  water  but  insoluble 
in  alcohol.  So,  if  an  emulsion  containing  gelatine  be  poured 
into  alcohol,  the  gelatine  will  form  a  clot,  the  water  being  re- 
moved from  it,  and  along  with  the  water  will  be  removed  a  great 
proportion  of  whatever  soluble  salts  it  contains — as  nitrates,  in 
this  instance.  In  the  ordinary  washing  process,  we  have  but 
little  control  over  the  quantity  of  water  which  will  be  absorbed 
by  the  gelatine,  so  that,  under  certain  conditions,  our  final 
emulsion  is  too  watery,  and  the  following  difficulty  arises :  If, 
during  the  "  setting "  of  the  gelatine  on  a  coated  plate,  the 
silver  bromide  is  allowed  to  sink  through  the  gelatine  down  to 
near  the  glass  or  other  "  support,"  the  quality  of  the  plates 
must  evidently  be  damaged  ;  if  the  emulsion  be  very  watery, 
this  sinking  will  surely  take  place,  and  the  coarser  the  "  grains  " 


THE   PROCESS K3    OF    PUKE    PHOTOGRAPHY.  63 

of  the  silver  haloid,  the  more  surely  and  more  rapidly  will  this 
detrimental  settling  take  place.  The  danger  and  the  damage 
increase  in  direct  ratio  with  the  sensitiveness  of  the  emulsion, 
or  the  grain-size  of  the  silver  haloid.  Again,  when  we  are 
dealing  with  exceedingly  sensitive  emulsion,  the  drying  of  the 
plates  is  a  process  fraught  with  danger  of  fog,  and  the  more 
prolonged  the  drying  the  greater  the  risk  of  fog.  Moreover, 
as  a  very  sensitive  emulsion  is  more  transparent  than  a  less 
rapid  one,  a  thicker  coating  of  the  former  than  of  the  latter  is 
required  to  give  a  robust  image.  We  need  surely  add  no  fur- 
ther arguments  in  favor  of  a  small  quantity  of  water  in  the 
finished  emulsion ;  and  by  the  washing  process  the  quantity  of 
water  is  a  factor  more  or  less  beyond  our  power  to  regulate, 
while,  by  precipitation,  it  is  reduced  to  the  minimum.  Some 
authorities  advocate  the  precipitation  method,  because,  by  it 
the  emulsion  acquires  a  greater  "  covering  power,"  in  other 
words,  because  less  emulsion  is  required  for  each  plate ;  the 
claim  is  well  founded,  though  we  would  warn  our  reader 
against  stinting  the  quantity  of  emulsion  allotted  to  each  plate. 
The  precipitation  process  is  certainly  commendable  for  very 
sensitive  ammonio  nitrate  emulsions.  The  practice  follows : 

Take  a  jar  fit  to  hold  at  least  four  times  the  quantity  of 
emulsion  to  be  treated  ;  into  this  place  ordinary  commercial 
alcohol,  in  quantity  two  or  three  times  as  great  as  the  quantity 
of  emulsion.  The  quantity  of  alcohol  varies  according  to  (1) 
the  quality  of  alcohol,  i.  e.,  the  quantity  of  water  in  it ;  (2) 
the  temperature  of  the  alcohol  and  of  the  emulsion.  The  higher 
these  temperatures  the  more  spirit  required.  Cool  the  alcohol 
to  40  deg.  Fahr.,  and  let  the  emulsion  be  as  cool  as  possible, 
consistent  with  fluidity,  and  alcohol  two  and  a  half  parts 
to  emulsion  one  part  ought  to  suffice  for  complete  coagulation. 

The  spirit  being  placed  in  the  larger  vessel  and  the  emul- 
sion about  90  deg.  Fahr.,  the  latter  is  poured  in  a  very  fine 
stream  into  the  former,  stirring  being  kept  up  with  a  glass 
rod  all  the  time.  Clots  will  form,  some  sticking  to  the  glass 
rod,  some  to  the  sides  and  bottom  of  the  jar.  When  no  fur- 
ther coagulum  is  formed,  the  whole  clot  is  to  be  pressed  hard 
into  one  lump,  over  which  a  few  ounces  of  fresh  alcohol 


64:  THE   PROCESSES    OF   PURE    PHOTOGRAPHY. 

should  be  poured.  We  have  now  a  comparatively  small, 
dense  mass  of  gelatine-clot  containing  all  the  silver  salts,  while 
the. large  vessel  contains  nearly  all  of  the  water  and  of  the 
bye-products.  The  clot  still  requires  a  careful  washing.  Tear 
it  up  with  the  fingers,  or  cut  it  with  scissors  into  very  small 
pieces,  which  are  to  be  placed  in  water  to  be  changed  fre- 
quently during  twenty-four  hours,  or  the  pieces  may  be 
washed  in  the  sieve  or  teapot,  as  in  last  chapter.  Light  should 
be  entirely  excluded  during  all  operations  where  it  is  not  abso- 
lutely essential,  and  in  any  case  the  light  used  must  be  of  the 
"  safest." 

When,  after  washing  and  "  dripping,"  this  emulsion  comes 
to  be  melted  up,  it  will  be  found  to  be  much  smaller  in  quan- 
tity and  thicker  in  consistency  than  the  batches  made  by  our 
previous  methods.  It  should,  after  solution  by  heat,  and  the 
addition  of  alcohol  and  thymol,  as  before,  be  made  up  with 
water  to  at  least  twelve  ounces. 

Separation  by  Centrifugal  Force. — By  this  process,  which, 
we  admit,  entails  extra  and  rather  expensive  apparatus,  not  only 
is  the  messy  and  tedious,  and,  at  the  best,  uncertain  process  of 
washing  done  away  with,  but  all  uncertainty  and  irregularity 
in  the  components,  and  consistency  of  the  finished  emulsion, 
are  entirely  eliminated.  Decomposed  gelatine,  and  its  too 
frequent  concomitant — fog — are  practically  banished,  and  in 
various  respects  the  ultimate  quality  of  the  emulsion  is  reduced 
to  a  matter  of  weights  and  measures.  The  process  is  applicable 
to  all  qualities  of  emulsion,  but  unless  the  principles  be  under- 
stood, the  practice  is  certain  to  be  conducted  wrongly,  and 
inevitable  trouble  and  possible  failure  will  arise. 

The  emulsion,  after  "  cooking,"  whether  by  the  boiling  or 
by  the  ammonio-nitrate  process,  is  placed  in  a  vessel  which  is 
caused  to  rotate  at  a  very  great  speed  on  its  own  axis.  By  the 
law  of  centrifugal  forces,  given  a  liquid  (as  water)  containing 
substances  not  in  solution  (as  silver  bromide,  iodide,  etc.),  the 
liquid  being  caused  to  rotate  rapidly  in  a  vessel  also  rotating, 
the  solids  not  in  solution  will  fly  outwards  from  the  centre  of 
rotation  with  force  and  velocity  directly  as  their  density. 
The  larger  the  diameter  of  the  rotating  vessel— i.e.,  the  longer 


THE   PROCESSES    OF    PURE    PHOTOGRAPHY.  65 

the  radius  of  revolution — the  less  is  the  speed  of  rotation 
required  to  produce  a  given  centrifugal  force  ;  vice  versa,  the 
smaller  the  diameter  of  our  vessel,  the  more  quickly  we  must 
cause  it  to  rotate  to  produce  a  given  effect.  The  whole  theory 
is  exceedingly  interesting,  but  we  cannot  follow  it  out  here. 

The  machine  used  in  Great  Britain  is  figured  here,  and  is 
made  by  Messrs.  Watson,  Laidlaw  &  Co.,  of  Glasgow.*  This 
figure  shows  the  smallest  size  made.  It  was,  indeed,  specially 
designed  for  amateurs  and  experimentalists,  and  the  "  drum  " 
is  so  constructed  as  to  be  used  in  daylight.  Larger  sizes  are 


FIG.  18. 

made  open  at  the  top,  for  use  in  the  dark-room,  and  the  larger 
sizes  may  be  driven  by  steam.  Into  our  small  size  (ty  inch 
"drum")  we  can  only  put  10  or  12  ounces  of  emulsion  at  a 
time,  but  into  the  larger  open  sizes  emulsion  can  be  poured  in 
enormous  quantities  as  separation  proceeds,  for  the  solids  stick 
to  the  sides  while  the  liquid  keeps  running  out.  The  whole 
apparatus  must  be  accurately  macle  to  insure  steady  running 
and  high  speed,  and  the  "  drum  "  is  made  of  metal  heavily 

*The  Eastman  Company  are  now  agents  for  these  machines. 


66  THE    PROCESSES    OF    PURE    PHOTOGRAPHY. 

silver-plated.  In  our  little  machine  the  drum  can  be  made  to 
revolve  about  four  thousand  times  per  minute  without  undue 
muscular  exertion,  and,  as  a  rule,  three  minutes  at  full  speed 
suffices  for  our  purpose. 

It  is  evident  that  the  denser  our  grains  of  silver  haloid,  and 
still  more,  the  more  completely  our  gelatine  is  decomposed  and 
has  lost  its  viscosity  by  cooking,  the  more  completely  will  our 
solids  (the  silver  salts)  separate  from  the  gelatine.  So  it  is 
that  the  more  sensitive  our  emulsion,  by  cooking,  has  been 
made,  the  more  quickly  and  the  more. markedly  is  our  separa- 
tion accomplished. 

We  place  our  cooked  emulsion  in  the  "drum,"  which  is  the 
name  given  to  the  revolving  vessel,  the  emulsion  being  at  a  tem- 
perature of  not  less  than  100  deg.  Fahr.  We  start  the  machine 
slowly  till  we  have  attained  the  highest  convenient  speed,  and 
that  speed  we  keep  up  for  not  more  than  three  minutes,  unless 
we  are  using  a  very  slow  emulsion.  There  should  be  at  least 
four  grains  of  gelatine  in  each  ounce  of  emulsion  actually  in 
the  drum.  If  there  is  a  larger  amount  of  gelatine,  no  harm 
will  be  done,  only  separation  may  be  a  little  more  protracted. 
Whatever  gelatine  is  present,  during  separation,  is  practically 
entirely  rejected  afterwards,  and  we  believe  that  decomposed 
gelatine  is  entirely  rejected,  which,  indeed,  is  one  of  our 
strongest  claims  for  the  process. 

There  is  not  much  fear  of  underdoing  the  separation,  but 
there  is  much  fear,  and  we  believe  a  frequent  habit,  of  over- 
doing it.  We  cannot  account  for,  we  can  only 'state,  the  fact 
that  over-separation  leads  to  a  thin,  weak,  and  even  foggy 
emulsion.  Our  separation  must,  therefore,  be  regulated  by  the 
sensitiveness  (grain-size)  of  the  emulsion,  quantity  of  gelatine 
present,  and  temperature.  The  larger  the  grain,  the  less  the 
proportion  of  gelatine,  and  the  higher  the  temperature,  the  less 
violent  or  prolonged  must  be  oar  separation.  If  we  find  we 
are  getting  into  thin,  weak,  or  foggy  emulsions,  we  may  either 
separate  less,  or  add  (say)  twenty  grains  per  ounce  of  gelatine 
before  separation.  It  has  been  recommended  in  case  of  thin- 
ness, etc.,  to  re-emulsify  for  a  time  with  a  small  quantity  of  a 
soluble  nitrate,  but  we  deprecate  any  such  plan.  If  our  emul- 


THE    PROCESSES   OF   PURE    PHOTOGRAPHY.  67 

sion  is  thin,  etc.,  we  simply  count  it  a  failure,  and  try  again, 
with  greater  precautions  than  before  ;  either  more  gelatine  or 
less  separation. 

The  separation  process  must  be  stopped  very  gradually  to 
prevent  "  scour "  inside  the  drum ;  that  is  to  say,  to  prevent 
the  liquid,  whirling  round  inside,  from  washing  off  the  silver 
salts  sticking  to  the  sides  of  the  drum.  If  the  drum  fits  loosely 
on  its  spindle  it  will  stop  slowly  of  itself,  if  not  the  motion  must 
be  regulated  down  to  a  standstill  with  the  handles. 

Separation  being  complete,  the  drum  is  carried  into  the 
dark-room,  and  opened  with  an  apparatus  which  accompanies 
each  machine  (for  the  lid  will  be  very  tightly  jammed. 

The  liquid  in  the  middle  is  carefully  poured  out  into  a 
beaker,  where  it  may  be  preserved  for  examination,  A  little 
cold  water  is  put  into  the  drum,  and  gently  carried  round  it, 
and  lastly  poured  out.  In  the  drum  nothing  remains  but  our 
silver  haloids,  bound  together  to  the  side  of  the  drum  by  a 
trace  of  normal  gelatine,  and  we  know  precisely  what  we  have 
to  deal  with.  If  we  are  making  a  twelve  ounce  batch  of 
emulsion,  as  last  described,  we  take  400  grains  of  hard  gelatine, 
as  Xelson's  X  Opaque,  soak  it  for  a  time  in  cold  water,  ten 
ounces,  and  with  the  soaked  gelatine,  a  little  at  a  time,  we  mop 
the  drum  out,  till  nothing  is  left  on  the  sides.  This  must  be 
carefully  and  thoroughly  done ;  and  when  separation  has  been 
very  complete,  as  with  a  very  rapid  emulsion,  long  separated,  a 
piece  of  clean  flannel  may  even  be  required  to  remove  the  solid 
substance  from  the  sides  of  the  drum.  We  do  not,  with  our  small 
drum,  and  a  small  batch  of  emulsion,  such  as  described,  like  to 
find  the  solids  sticking  very  tightly  to  the  drum  ;  this  a  sign  of 
over-separation.  Where  large  quantities  of  emulsion  have 
been  separated,  and  where  the  operation  has  been  protracted, 
the  stuff  is  always  in  close  adherence  to  the  drum,  especially 
that  next  to  the  sides. 

Our  soaked  gelatine  is  now  covered  with  a  mass  of  gray 
silver  bromide  and  gelatine ;  alcohol  is  added,  as  before,  and 
heat  gently  applied,  during  which  the  bromide  and  the  gela- 
tine must  be  most  thoroughly  incorporated  by  stirring,  or  even 
switching.  We  have  now  a  batch  of  emulsion  of  which  we 


68  THE    PEOCES8ES    OF    PUKE    PHOTOGRAPHY. 

know  the  ingredients  to  a  fraction.  Decomposed  gelatine 
is  entirely  absent,  and  with  it  red  fog  and  other  plagues 
frequently  accompanying  washing  processes. 

A  plate  may  be  coated  for  test  at  once,  but  it  is  much  better 
to  let  the  emulsion  cool  and  set  at  least  once  before  use. 
Each  subsequent  melting  of  an  emulsion  increases  its  rapidity 
to  an  appreciable  extent ;  too  many  meltings  may  fog  it. 

A  word  or  two  on  the  quality  of  gelatine  used  for  the  bulk 
of  the  emulsion.  An  acid  gelatine  is  not  adapted  for  giving 
the  highest  sensitiveness  to  the  plates,  and  an  alkaline  soft 
gelatine  is  apt  to  frill  or  melt  in  hot  weather.  We  try  to 
steer  clear  of  these  defects  by  using  either  a  "  hard  "  alumin- 
ated  gelatine  washed  in  alkaline  water,  or  a  "  soft "  gela- 
tine treated  with  chrome  alum  added  with  the  alcohol  at  the 
last  stage.  But  once  the  emulsion  becomes  dry,  in  presence  of 
alum  it  cannot  again  be  dissolved,  so  it  is  necessary  to  add  the 
alum  only  to  such  quantity  as  can  be  used  at  once. 


CHAPTER    XI. 

COATING  PLATES  WITH  GELATINE  BROMIDE 
EMULSION,  DRYING    ETC. 

THE  glass  used  for  coating  with  gelatine  emulsion  must  be 
quite  clean,  but  need  not  be  polished  to  such  a  degree  as  is 
required  for  wet  collodion.  But  when  we  come  to  the  opera- 
tion of  coating  the  plates,  a  considerable  difference  will  be 
found  between  coating  a  half-dirty  and  a  well-cleaned  plate. 
Plates  that  have  been  used  before  should  be  bathed  for  some 
days  in  weak  acid,  one  part  of  hydrochloric  or  nitric  acid  to 
twenty  of  water.  If  the  film  previously  on  the  plate  was 
gelatine,  washing  in  hot  water  should  follow.  In  any  case 
the  plates  should  be  bathed  for  a  few  minutes  in  a  hot  solu- 
tion of  washing  soda,  and  then  well  washed  under  a  tap. 
Next,  a  creamy  mixture  of  whiting  and  water  is  made,  rubbed 
with  a  clean  pad  of  cloth  or  flannel  all  over  the  plate,  and  set 
aside  till  the  whiting  is  dry  and  easily  dusted  off.  It  should 
be  dusted  off,  special  attention  being  given  to  the  edges  of  the 
plate,  and  the  plate  finally  polished  with  a  clean,  dry  cloth. 
The  plates  are  then  racked  or  laid  in  a  pile  till  required.  If 
the  plates  be  rinsed  over  with  a  weak  solution  (one  per  cent.) 
of  chrome  alum  carefully  filtered,  frilling  will  be  obviated  in 
the  hottest  weather  (Henderson.) 

Coating. — The  emulsion  is  to  be  melted  by  heat,  but  at  the 
time  of  coating  the  temperature  should  not  exceed  110  deg., 
or  120  deg.  Fahr.  at  the  very  highest.  So  long  as  the  emulsion 
will  flow  readily  and  not  set  on  the  plate  with  inconvenient 
haste,  it  can  hardly  be  too  cool.  If  the  weather  is  very  cold 
the  plates  may  have  the  "  chill  off,"  but  anything  like  heat- 
ing them  is  a  source  of  danger.  What  we  have  to  avoid  is 
the  setting  taking  too  long,  and,  consequently,  the  silver 


TO  THE    PROCESSES    OF    PURE    PHOTOGRAPHY. 

bromide  sinking  through  the  gelatine  to  or  towards  the  glass 
plate.  The  bromide  should  be,  so  far  as  possible,  kept  in  the 
upper  stratum  of  the  film. 

The  "setting-table,"  with  its  slab  of  marble,  glass,  or  slate, 
being  arranged  dead  level,  and  being  within  reach  of  the 
operator's  hand,  while  he  stands  at  the  coating  table;  the 
emulsion  jar  being  placed  in  a  considerable  quantity  of  water 
of  the  proper  temperature,  and  the  light  being  arranged  so 
that  the  operator  may  easily  examine  the  film,  all  is  in  readi- 
ness for  a  start.  The  emulsion,  if  not  previously  filtered, 
must  be  filtered  now,  and  this  may  be  done  in  several  ways. 
Perhaps  the  simplest  way  is  to  use,  for  coating,  an  earthen, 
ware  tea-pot,  having  in  place  of  a  lid  a  bag  of  swan's-down 
calico,  supported  by  either  a  wire  hoop  or  an  elastic  band 
around  the  top  of  the  pot,  and  the  bag  dipping  down  to  the 
very  bottom  of  the  tea-pot.  The  tea-pot  is  placed  in  the  hot 
water,  and  all  the  emulsion  is  poured  into  it  through  the  bag 
before  it  is  poured  upon  the  plates,  or  the  emulsion  may  be 
filtered  through  swan's-down  calico  into  an  open-mouthed  jar 
in  the  hot  water,  and  a  silver  ladle  used  to  pour  the  emulsion 
upon  the  plate.  As  a  novice  is  sure  to  be  at  a  loss  how  much 
emulsion  to  put  on  each  plate,  we  recommend  a  silver  ladle 
with  a  "lip"  and  a  wooden  handle — an  ancient  "toddy 
ladle "  is  the  article  we  mean — or  a  ladle  may  be  made  on 
the  old  pattern  so  as  to  hold  a  given  quantity.  Our  ladle  for 
plates  10x8  holds  just  an  ounce,  for  7x5  or  8x5  just  half  an 
ounce.  It  is  impossible  to  regulate  the  quantity  exactly,  as 
"  a  little  "  is  usually  run  off  the  plate  in  some  cases,  and  much 
depends  on  the  quality  of  the  emulsion  and  the  purpose  for 
which  the  plates  are  intended.  The  emulsion  must  be  much 
thicker  on  the  plate  than  would  appear,  to  a  beginner,  neces- 
sary ;  thinly  coated  plates  have  of  late  promised  fair  to  damage 
the  reputation  of  all  concerned. 

If  the  plates  are  well  cleaned,  and  the  emulsion  in  good 
order,  the  coating  should  be  possible  almost  as  with  collodion  ; 
but  if  the  emulsion  has  any  tendency  not  to  run  evenly  over 
the  plate,  the  finger  in  one  case,  or  the  bottom  of  the  ladle  in 
the  other,  may  be  used  to  guide  it  over  the  plate.  The  spout 


THE    PROCESSES    OF   PUEE    PHOTOGRAPHY.  71 

of  the  teapot  or  the  lip  of  the  ladle  are  to  be  brought  close  to 
the  plate  ;  the  emulsion  must  not  be  poured  from  a  height,  else 
bubbles  will  form.  The  emulsion  is  to  be  poured  nearer  the 
centre  of  the  plate  than  when  collodion  is  used,  but  still  not 
right  in  the  centre.  If  too  much  emulsion  is  on  the  plate,  the 
excess  is  to  be  rejected  by  a  quick  and  short  "tipping"  of  the 
plate  over  a  clean  and  separate  jar,  placed  in  the  hot  water ; 
nothing  like  "  draining "  is  permissible,  as  the  film  would  be 
too  thin.  The  plate  may  be  held  in  the  fingers,  but  a  pneu- 
matic holder  (Fig.  13)  is  superior  to  the  hand.  The  operator 
must  not  mind  if  a  little  emulsion  flows -over  the  edge,  he 
should  have  a  large  flat  dish  below  his  hand,  to  catch  any  such 
overflow.  We  do  not  know  at  what  rate  plates  can  be  coated 
by  hand,  but  we  usually  expect  to  coat  two  10  x  8  plates  per 
minute. 

To  test  whether  each  plate  has  a  sufficient  quantity  of  emul- 
sion, we  examine  the  plate,  after  it  has  set,  by  a  gas  or  lamp 
flame,  behind  clear  ruby  glass.  If  we  can  see  the  shape  of  the 
flame,  the  plate  is  too  thinly  coated  for  negative  purposes  at 
least. 

The  plate  is  laid  on  the  level  cooling  slab,  as  quickly  as  pos- 
sible, after  an  even  film  has  been  obtained  on  the  plate  in  the 
hand.  The  sooner  the  plate  sets  after  this  the  better.  Three 
minutes  should  suffice  for  the  setting ;  if  five  minutes  are 
required,  ice  must  be  used  to  cool  the  slab.  As  a  rule,  except 
in  the  very  warmest  weather,  our  plates  are  set  at  the  end  of 
two  minutes,  and  sometimes  very  much  sooner.  To  ascertain 
whether  the  gelatine  is  set,  or  not,  a  corner  of  the  plate  may 
be  touched  with  the  finger,  but  in  no  case  must  a  plate  be 
lifted  before  it  is  set ;  a  plate  raised  from  the  level  when  just 
setting,  or  partly  set,  is  a  plate  ruined. 

As  soon  as  the  setting  is  certainly  complete,  the  plates  are 
dried  in  a  drying-box,  press,  or  room,  as  already  described. 

Drying  should  not  take  less  than  five  or  six,  nor  more  than 
eighteen  or  twenty  hours.  Twelve  hours  will  be  found  a  suit- 
able time.  When  once  the  plates  are  in  the  drying  receptacle 
and  shut  in,  the  door  must  not  be  opened  for  many  hours — 
not  until  the  plates  are  expected  to  be  dry — nor  should  there 


72  THE    PROCESSES    OF    PUKE    PHOTOGRAPHY. 

be  any,  even  temporary,  change  or  cheek  of  the  draught,  as 
these  things  will  surely  lead  to  "  drying-marks,"  which  are 
beyond  cure,  and  very  unsightly  wherever  they  appear.  If 
plates  take  longer  than  thirty-five  to  forty  hours  to  dry,  drying 
marks  may  be  looked  upon  as  almost  inevitable.  Heat  may  be 
used  to  provoke  a  current  of  air,  but  heated  air  should  not 
reach  the  plates,  still  less,  as  we  said  before,  any  burnt  air. 

Packing  Plates. — When  the  plates  are  perfectly  dry  they 
may  be  placed  in  plate-boxes  or  packed  in  boxes  of  cardboard. 
The  plates  should  be  packed  face  to  face,  and  between  each 
pair  of  faces  should  be  put  a  piece  oipure  tissue-paper  the  full 
size  of  the  plate,  kept  for  some  days  beforehand  in  the  dark,  and 
absolutely  dry.  It  is  no  use  to  pack  carefully  away  blemished 
plates,  which  would  only  lead  to  disappointment  at  critical 
junctures.  The  plates,  as  they  leave  the  drying-box,  should  be 
examined,  the  good  ones  packed  carefully  for  special  work, 
the  blemished  ones  placed  aside  for  experimental  work,  of 
which  too  much  cannot  be  done. 


CHAPTER  XII. 
THE    CAMERA  IN  THE    FIELD. 

To  DO  full  justice  to  this  heading  a  long  book,  instead  of  a 
short  chapter  in  a  little  book,  would  be  required.  "We  must, 
however,  exercise  our  ingenuity?  and  try  in  a  brief  chapter  to 
give  such  hints  as  may  enable  any  intelligent  reader  to  make  a 
public  appearance  with  his  camera,  and  without  "  shame  and 
confusion  of  face."  As  indoor  photography  at  the  best  pre- 
sents certain  difficulties  of  technique  not  likely  to  be  overcome 
without  some  practice,  we  propose  to  assume  that  the  first  set 
of  photographic  operations  by  the  tyro  will  be  conducted  out- 
of-doors.  In  most  cases  a  friend  is  the  victim  first  immolated 
on  the  altar  of  photographic  ambition ;  but  let  us  warn  our 
gentle  reader  that  there  is  no  surer  way  to  jeopardize  friendship, 
or  to  bring  contempt  on  ourselves,  than  to  try  our  prentice 
photographic  hand  on  a  human  subject.  The  best  subject,  if 
we  could  only  persuade  our  reader  to  take  our  advice,  is  some- 
thing in  the  nature  of  a  bust  or  a  carved  object  of  some  sort, 
placed  in  a  well-lighted  situation  out-of  doors. 

But,  to  save  space,  let  us  suppose  our  first  attempt  to  be 
made  on  a  landscape :  a  foreground,  let  us  say,  of  bushes,  a 
house  or  a  pool  of  water  in  the  mid-distance,  and,  about  one 
hundred  yards  away,  a  clump  of  trees.  The  sun  must  be 
neither  straight  behind  nor  right  in  front  of  us,  but  slightly 
behind  the  camera  on  one  side  or  the  other.  We  shall  suppose 
that  a  dry  plate  is  to  be  used,  in  which  case  we  have  with  us  a 
dark-slide  containing  a  plate,  which  slide  we  always  keep 
carefully  shielded  from  strong  light  in  a  case  of  some  sort. 
American  cloth  does  well  for  the  cases,  and  a  number  may  be 
painted  on  the  glazed  outside  of  the  cloth,  so  that  we  know  what 
slides  we  are  going  to  use. 


74  THE    PROCESSES    OF    PURE    PHOTOGRAPHY. 

First,  we  set  up  our  tripod,  the  leg-points  on   solid  ground, 
not  on  stones,  or  bits  of  wood,  which  may  move  away  and  over- 
set the  camera  ;  the  triangle,  or  tripod  head,  nearly  level.    We 
fix  our  camera  to  the  tripod  head  in  the  usual  way,  screw 
home   our  lens,  tie  or  button  upon  the  camera  the  "  black- 
cloth."     One  leg  of  the  tripod  stand  is  to  point  to  the  view,  the 
other  two  to  stretch   to  right  and  left  of  the  operator,  the 
ground-glass  about  the  height  of  the  operator's  mouth.     With 
our  head  under  the  cloth,  we  now  look  at  the  image  on  the 
ground-glass ;  ten  to  one  it  is  not  arranged  anything  like  as  we 
require  it.     The  first  thing  to  do,  if  not  already  done  in  opening 
the  camera,  is  to  get  roughly  the  focus,  which  is  done  with  the 
rack  and  pinion  of  the  camera.     The  first  step  toward  arrang- 
ing the  view  as  we  wish  it  on  the  ground-glass,  is  to  take  the 
two  legs  to  right  and  left  of  us,  one  in  each  hand,  leaving  the 
front  leg  firm  in  the  ground,  and  regulating  the  height,  aspect, 
and  level  of  the  camera,  by  the  two  legs  in  our  hands.     The 
ludicrous  public  exhibitions,  such  as  are  too  often  seen,  will  be 
entirely  obviated  by  this  system  of  grasping  two  legs,  and 
using  the  front  one  as  a  pivot.     Having,  after  this  manoeuvre, 
planted  the  camera  firmly  once  more  with  the  view  approxi- 
mately on  the  ground-glass  as  desired,  any  further  slight  altera- 
tions may  be  made  by  slightly  shifting  one  leg  at  a  time.    By 
means  such  as  these  the  camera  should  be  got  as  nearly  level  as 
the  eye  can  judge.     The  camera  may  be  twisted  on  its  screw 
from  side  to  side,  so  that  the  worker  may  study  the  composi- 
tion of  the  picture  at  various  angles.     A  beginner  is  sure  to  be 
greatly  puzzled  by  two  things :     1st.  The  fact  that  the  view  is 
seen  upside  down  on  the  ground-glass.     2d.  The  unexpectedly 
lovely  coloring.     To  both  of  these  he  will  become  habituated 
by  practice.     The  color  is  a  matter  of  very  great  import,  how- 
ever, and  is  apt  to  puzzle  the  most  experienced ;  for  the  very 
colors  that  look  so  charmingly  bright  on  the  ground-glass,  are 
the  very  ones  that  ordinary  photography  renders  as  shadows, 
viz  :  yellows,  reds,  and  greens. 

Perhaps,  even  yet,  the  arrangement  of  view  on  the  focusing 
screen  is  not  to  our  mind.  We  have  several  "  motions "  yet 
in  reserve.  The  front  of  the  camera  may  be  raised  to  cut  off 


THE    PROCESSES    OF    PURE    PHOTOGRAPHY.  75 

foreground,  or  get  into  the  picture  the  top  of  the  house  or  of 
the  tree.  Tilting  the  camera  is  only  recommended  as  a  last 
resource,  raising  the  front  must  be  tried  first.  Having  got  the 
view  as  nearly  to  our  taste  on  the  ground-glass  as  possible,  we 
insert  a  medium-sized  "  diaphragm  "  or  "  stop  "  in  the  lens, 
and  focus  carefully  with  a  Kamdsen,  or  other  eye-piece,  or  with 
the  naked  eye.  If  the  insertion  of  the  stop  shuts  out  too  much 
light,  and  makes  the  view  appear  too  dark,  remove  the  stop, 
or  substitute  a  larger.  In  focusing,  attention  should  be  chiefly 
directed  to  the  chief  object,  or  "motif"  of  the  picture,  and 
that,  as  a  general  rule,  should  be  neither  in  the  centre,  nor 
near  one  side.  Possibly  it  will  be  found  impracticable  to  get 
foreground  and  distance  in  decent  focus  at  one  time,  this  will 
be,  to  a  great  extent,  cured  when  a  small  stop  is  inserted,  and 
after  a  little  practice  the  swing-back  may  be  used  to  meet 
this  difficulty,  but  we  deprecate  the  use  of  the  swing-back  by  a 
beginner.  Many  workers  focus  on  the  foreground,  paying  no 
attention  to  the  distance  whatever,  but  trusting  to  stops  to  put 
all  right. 

The  focus  being  adjusted,  we  have  next  to  determine  what 
stop  to  use  in  the  lens.  Practically  the  issue  lies  between  three 
stops  -j^,  -/p,  and  -/%.  A  larger  stop  than  -^  is  seldom  used  for 
landscape,  and  a  smaller  than  /^  is  seldom  needed.  Of  course, 
the  smaller  the  stop,  the  sharper  the  focus,  and  the  longer  the 
exposure.  In  Chapter  III.  we  pointed  this  out,  but  we  repeat 
that  •/•%  requires  twice  the  exposure  of  -/^,  and  ^  twice  the 
exposure  of  ^.  (We  omit  decimals).  If  there  is  anything 
moving,  or  likely  to  move,  in  our  view,  we  must  use  the  largest 
stop  that  will  give  reasonable  definition  ;  while  the  larger  the 
distance  through  which  our  view  spreads,  from  front  to  back, 
the  smaller  the  stop  required  to  insure  reasonable  sharpness. 

We  most  earnestly  urge  not  only  the  beginner  but  the  more 
•  practised  hand  not  to  muddle  among  too  many  stops.  Practi- 
cally we  use  but  two  stops,  -^  when  we  must  expose  quickly, 
-^  when  there  is  no  hurry.  In  a  few  cases,  as  in  a  very  dark 
glen,  where  the  exposure  with  -/j  would  be  very  considerable, 
we  sometimes  use  /j,  but  this  is  very  rare  in  landscape  work. 
The  photographer  has  quite  enough  of  varying  circumstances 


76  THE    PROCESSES    OF    PURE    PHOTOGRAPHY. 

beyond  his  control  without  varying  operations  within  his 
command. 

If  the  subject  includes  parallel  vertical  or  horizontal  lines, 
as  in  architecture,  some  further  considerations  require  notice, 
and  the  following  remarks  apply  particularly  to  cases  where 
the  architecture  either  fills  a  large  portion  of  the  plate  or  falls 
near  the  edge  of  the  picture.  In  such  a  case  the  first  necessity 
is  that  the  camera  shall  be  dead  level.  But,  possibly,  the 
whole  of  the  building  will  now  not  ';  come  into "  the  plate. 
The  first  expedient  is  to  go  as  far  away  from  the  building  as 
possible.  Failing  that,  if  the  top  of  the  building  will  not 
come  into  the  field,  the  front  of  the  camera  must  be  raised  as 
far  as  it  will  go  without  letting  light  into  the  camera.  Failing 
that,  the  vertical  position  of  the  plate  may  be  tried,  by  reversing 
the  back  or  turning  the  camera  on  its  side.  If  this  is  not 
satisfactory,  the  camera  must  be  tilted  upwards,  always  suppos- 
ing we  have  only  one  lens.  A  shorter  focus  lens  might,  of 
course,  remove  the  difficulty  ;  but  tilting  the  camera  upwards 
will  at  once  cause  the  straight  lines  of  the  building  to  be 
"  distorted,"  and  in  that  case  we  must  use  the  swing-back. 
The  lower  part  of  the  swing-back  must  be  drawn  out,  or  the 
upper  part  pushed  forward,  till  the  ground-glass  hangs  verti- 
cal— parallel,  that  is,  with  the  lines  of  the  building— and  in 
this  case  a  very  small  stop  is  required,  for  reasons  into  which 
we  cannot  enter  here. 

The  Swing-back  is  very  frequently  totally  misunderstood 
and  shamefully  abused,  the  reason  being  that  photographers 
do  not  know,  or  at  least  fail  to  realize,  that  the  swing-back 
has  two  uses  totally  distinct  from  each  other.  The  uses 
of  the  swing-back  are:  (1st)  that  suggested  a  few  lines 
higher,  viz.,  to  prevent  distortion  when  the  camera  is  tilted, 
and  (2d),  to  aid  in  getting  into  simultaneous  focus  a  near 
object  and  a  distant  one.  On  (1)  we  have  said  all  that  seems 
necessary ;  on  (2)  a  few  words  may  not  be  wasted.  The  focus 
for  an  object  close  to  the  lens  is,  as  everybody  must  have 
observed,  further  back  or  further  from  the  lens  than  the  focus 
for  an  object  at  a  considerable  distance  away ;  so  that  with  the 
ground-glass  hanging  vertical  when  a  distant  object  is  in  focus 


THE    PROCESSES    OF    PUKE    PHOTOGRAPHY.  77 

the  image  of  a  near  object  is  in  front  of  the  focus  and  blurred. 
If  we  focus  on  the  middle  distance,  or  on  an  object  (say)  fifty 
times  the  focus  of  the  lens  distant  from  the  camera,  both  the 
distance  and  the  foreground  are  out  of  focus,  the  distance  on 
the  ground-glass  being  behind  the  best  focus  and  the  fore- 
ground in  front  of  its  best  focus.  Plainly,  therefore,  if  our 
swing-back  works  on  its  centre,  as  every  swing-back  ought  to 
do,  and  if  we  pull  the  top  of  the  swing-back  backwards, 
we  shall  also  push  the  bottom  of  it  forward,  so  that  the  middle 
distance  will  remain  in  focus  and  the  foreground  and  far  dis- 
tance will  each  find  its  proper  focus.  With  a  central-swing 
this  is  plain  enough,  but  with  a  swing-back  working  from  the 
top  on  a  pivot  at  the  foot,  we  are  very  apt  to  make  the  general 
focus  far  worse  than  it  was.  With  such  a  swing-back,  which 
is  usually  a  swinging  of  the  whole  back  of  the  camera,  we  must 
either  focus  on  the  distance,  and  then  pull  back  the  .upper  part 
till  the  foreground  is  focused,  or  we  must  pull  the  top  towards 
us  first,  and  try  to  focus  thereafter,  a  very  awkward  and  uncer- 
tain proceeding  at  the  best.  The  first  use  of  the  swing-back — 
to  prevent  distortion — necessitates  the  use  of  a  small  stop ;  the 
second  use,  to  a  great  extent,  obviates  the  necessity  for  a  stop, 
or,  at  any  rate,  permits  of  the  use  of  a  larger  stop.  In  all 
cases  the  focus  should  be  examined  after  the  use  of  the  swing- 
back. 

We  shall  leave  consideration  of  what  would  naturally  follow 
here,  viz.,  exposure,  until  we  have  touched  briefly  on  a  few 
other  circumstances  frequently  met  with  in  the  field. 

It  is  well  to  have  as  few  detached  articles  as  possible  when 
going  into  the  field.  The  tripod  screw  should  either  be  let 
into  the  head,  so  as  not  to  come  out  unless  purposely  removed, 
or  it  should  be  tied  to  some  part  of  the  stand.  The  stops 
should  not  only  be  tied  to  the  lens  (if  Waterhouse  stops  are  , 
not  fixed  in  the  lens  tube),  but  they  should  be  riveted  together 
in  such  a  way  as  to  allow  the  one  required  to  be  turned 
aside  from  the  others  when  it  is  used.  The  lens  cap  may 
be  tied  to  the  lens  by  raising  a  small  portion  of  the  velvet 
lining  the  cap,  boring  a  hole  through  the  leather,  passing  a  bit 
of  catgut  through  the  hole,  knotting  the  end  inside  the  cap, 
and  then  replacing  the  velvet  with  glue  over  the  knot. 


78  THE    PROCESSES    OF    PUKE    PHOTOGRAPHY. 

It  is,  of  course,  necessary  to  avoid  exposing  the  same  plate 
twice.  Various  devices  are  used  to  render  this  mishap  impos- 
sible. In  America  a  shutter  is  used  for  the  dark  slide,  having 
on  one  side  the  word  "  exposed,"  in  large  letters  ;  after  expos- 
ure this  shutter  is  replaced  with  the  legend  outwards.  A 
device  is  used  in  England  whereby  the  shutter,  once  drawn 
and  closed,  cannot  be  again  drawn  without  set  purpose  and 
special  operations.  A  beginner  during  a  big  day's  work  is 
pretty  certain  to  "double  expose"  a  plate  now  and  again, 
nothing  but  care  and  deliberation  can  prevent  it,  unless  some 
mechanical  device,  such  as  suggested  above,  is  used.  When  a 
roll-holder  is  In  use,  one  very  often  forgets  at  the  critical 
moment  whether  the  paper  has  been  rolled  off  since  last 
exposure,  and  very  painful  doubt  harasses  the  worker.  We 
recommend  that  the  rolling  be  performed  immediately  after 
each  exposure  is  made.  This  is  the  time  when  the  mental 
strain  is  over,  and  often  there  is  a  hurry  when  the  next  expos- 
ure draws  near.  Dust  has  no  business  to  get  into  a  roll- 
holder,  and  if  it  does  get  in  it  will  do  as  much  damage  to  an 
exposed  as  to  an  unexposed  surface  of  film. 

Everyone  should  carry  a  note-book,  and  note  in  it  every 

exposure  made.     Books  ruled  for  the  purpose  with  suitable 

columns  are  to  be  had,  but  probably  an  unruled  book  is  quite 

as  good,  for  frequently  the  ruled  columns  do  not  allow  of 

enough  space  being  filled  in  special  cases.     Under  the  head  of 

"  remarks  "  we  include  a  description  of  the  nature  and  chief 

characteristics  of  the  view,  the  points  we  wish  to  bring  out, 

"the  nature  of  negative  required;  and  with  such  details  we 

V  sometimes  fill  halt' a  page  of  any  ordinary  pocket-book. 

To  test  a  camera  for  "light-tightness"  put  a  lens  in  its 
place,  a  stop  in,  and  the  cap  on.  Place  an  ample  black  cloth 
*  over  the  back  of  the  camera  as  near  the  ground-glass  as  pos- 
sible. Place  the  dark  cloth  over  the  head  and  draw  it  tightly 
around  the  neck  so  as  to  prevent  any  light  entering  the  camera 
from  behind  the  operator.  The  ground-glass  being  turned 
away  or  removed,  take  the  camera  up  in  the  hands,  gaze  earn- 
estly for  at  least  a  minute  into  the  interior  of  the  camera  in  a 
blaze  of  sunlight,  or  (even  better)  near  a  strong  gas  or  lamp 


THE    PROCESSES    OF   PURE    PHOTOGRAPHY.  79 

flame.  Holding  the  camera  in  the  hands  and  the  face  close 
to  the  open  camera  back,  turn  the  camera  in  every  direction, 
up  and  down,  to  the  right  and  left,  over  on  one  side,  then  on 
the  other,  always  close  to  the  light,  if  artificial.  Any  small 
hole  will  soon  be  detected.  We  have  repeatedly  found  new 
cameras  defective  in  this  matter.  The  stop-slit  of  most  lenses 
lets  in  light ;  this  is  a  piece  of  gross  carelessness  on  the  part 
of  the  makers,  and  must  be  remedied  by  a  broad  rubber  band 
with  a  short  slit  made  lengthwise  to  take  the  finger-piece  of 
the  stop. 

The  advantages  of  sliding  legs  for  the  tripod  are  found  out 
not  only  when  working  on  very  uneven  ground,  but  in  certain 
other  cases  where  the  camera  ought  to  be  very  low.  Where 
there  is  a  large  exposure  of  foreground  objectionable  or 
uninteresting,  as  the  bed  of  a  river  or  the  water  of  a  lake  ;  or 
where  we  wish  to  emphasize  height,  as  of  waves  or  mountains, 
the  camera  can  hardly  be  put  too  low.  For  such,  views  it  is 
frequently  advisable  to  place  the  camera  so  near  to  the  ground 
that  we  require  to  sit  or  even  lie  down  in  order  to  focus. 

Photography  of  interiors  presents  so  many  exceptional 
phases  that  it  may  almost  be  called  a  separate  process.  As  a 
rule,  the  camera  requires  to  be  mounted  to  a  considerable 
height  for  this  work,  and  here  again  sliding  legs  are  useful. 
Frequently  the  floors  of  edifices  are  slippery,  and  the  sharp 
metal  "  shoes "  of  the  tripod  will  not  grip  to  floor.  The 
sloping-marble  roof  of  Milan  Cathedral  was  the  most  slippery 
place  with  which  we  have  ever  dealt ;  we  overcame  the  trouble 
by  placing  under  our  tripod  feet  thick  discs  of  leather  wetted 
previously.  Corks,  into  which  the  sharp  points  of  the  legs 
are  stuck,  frequently  answer  the  purpose. 

For  cases  of  exceptional  difficulty,  as  for  instantaneous 
"  shots "  from  and  at  moving  objects,  there  are  so  many 
devices  to  be  found  in  the  market  that  it  would  be  hopeless 
for  us  to  attempt  to  describe  them.  We  refer  to  Detective 
cameras,  and  a  host  of  "  view-meters  "  and  "  finders,"  many 
of  them  sufficiently  ingenious  to  catch  the  dollars  of  the  ama- 
teur, if  not  the  images  of  the  moving  objects  they  are  intended 
to  catch.  Of  '.'  finders/'  some  are  practically  useful,  we  may 


SO  THE    PROCESSES    OF    PUKE    PHOTOGRAPHY. 

mention  one,  called  in  America,  the  "  "Waterbury,"  and  in 
England  the  "Argus,"  which  fairly  answers  its  purpose. 

For  "  focusing  and  finding "  simultaneously,  no  device  that 
we  know  is  of  any  value,  except  such  as  amounts  practically  to 
a  second  camera,  furnished  with  a  second  lens  of  the  same 
focal  length  as  the  lens  in  the  camera  proper.  True,  the 
secondary,  or  "  finding  and  focusing,"  camera  is  generally 
smaller  than  the  working  camera ;  an  example  of  this  is  found 
in  the  small  telescope  suggested  by  Mr.  J.  Traill  Taylor. 
This  telescopes  fits  along  the  top  or'  side  of  the  camera,  and 
opens  out  as  the  camera  opens ;  and  the  lens  of  the  telescope 
is  of  the  same  focal  length  as  the  camera  lens  but  of  much 
simpler  and  cheaper  construction. 

Another  suggestion  made  lately  is  to  erect  on  the  front  of 
the  camera  over  the  lens  another  lens  of  equal  focus,  to  turn 
the  ground-glass  of  the  camera  up  so  that  it  may  stand  verti- 
cally over  its  usual  position.  The  "finding"  lens  will  cast 
an  image  on  the  erect  ground-glass,  which  image  will  be 
visible  under  the  black  cloth,  if  not  without  it.  When  these 
"finders  and  focusers"  are  being  used,  the  shutter  of  the 
dark  slide  is,  of  course,  open,  and  the  instantaneous  shutter 
set  for  work;  so  that  when  in  the  "finding"  arrangement 
the  object  is  seen  in  the  desired  position  and  focus,  the  expos- 
ure is  made  with  the  instantaneous  shutter  in  the  usual  way. 


CHAPTER  XIII. 

EXPOSURE    AND    DEVELOPMENT    GENERALLY 
TREATED. 

AT  the  end  of  this  book  will  be  found  a  table  compiled  for 
the  purpose  of  assisting  the  beginner  to  form  an  approximate 
idea  as  to  how  long  he  should  expose  a  plate  under  various 
circumstances;  but  it  must  be  clearly  understood  that  this 
table  is  intended  merely  approximately  correct,  and  by  no 
means  to  be  taken  as  infallible,  or  as  a  crutch,  to  be  depended 
upon  by  the  worker  of  experience.  Nothing  but  practice  can 
ever  teach  the  proper  exposure,  and  if  our  table  should  cause 
any  reader  to  use  it,  or  any  other  "  table  of  exposures,"  as  other 
than  aid  to  the  tyro,  we  should  regret  having  given  it.  The 
table,  however,  obviates  the  necessity  of  our  giving  further 
special  hints  for  any  cases  coming  under  such  heads  as  will  be 
found  in  the  table.  The  old  rule  is  to-day  just  as  good  as  the 
day  it  was  first  enunciated — "  Take  care  of  the  shadows,  and 
the  lights  will  take  care  of  themselves." 

A  "  good  technical  negative  "  is  a  very  elastic  phrase  ;  still 
it  is  a  useful  one.  Our  negative  must  first  be  such  as  will 
give  a  "  good  print."  A  good  print  is  one  that  will  justly 
represent  the  aspect  we  wish  to  portray.  Whatever  else  a 
negative  may  be,  it  must  be  clean,  and  must  be  within  certain 
undefinable  limits  of  density  and  thinness.  All  the  details 
visible  on  the  subject  must  certainly  be  present  in  the  print, 
and  "  clear  glass  "  ought  to  have  no  place  on  a  negative,  what- 
ever others  may  say. 

Luckily  for  the  artistic  side  of  photography,  it  is  not  the 
case  that  there  is  only  one  exposure  and  only  one  develop- 
ment which  will  give  a  perfect  negative.  A  brilliant  negative 
may  be  quite  as  perfect  as  a  tender  or  soft  one ;  and  if  we  are 


82  THE    PROCESSES    OF   PCKE    PHOTOGRAPHY. 

to  claim  any  art  for  photography,  we  must  be  able  to  produce 
at  will  a  good  negative  of  any  desired  kind,  brilliant  or  soft, 
"  plucky,"  or  "  harmonious." 

Exposure  and  development  hang  together.  One  is  useless 
without  the  other ;  one  may  nullify  the  other ;  one  may 
emphasize  the  other ;  we  may  produce  many  different  aspects 
of  a  view  by  various  negatives — all  good  negatives. 

Our  next  remarks  will  be  devoted  to  showing  how  various 
aspects  or  qualities  may  be  produced  on  various  negatives — all 
good — by  various  treatments,  all  equally  scientific. 

There  is  a  minimum  exposure,  the  least  that  will  permit  of 
the  production  of  a  good  technical  negative.  There  is  a 
maximum  exposure,  the  greatest  that  can,  without  abnormal 
development,  be  given  without  ruin  to  the  technique  of  the 
negative ;  and  there  is  a  normal  exposure  midway  between  the 
two,  what  scientifically  may  be  called  "  the  correct  exposure," 
though,  artistically  speaking,  there  are  many  correct  exposures. 
Taking  the  normal  exposure  as  our  standard  of  comparison, 
we  say. 

1.  Long  exposure  leads  to  softness,  harmony,  effeminacy. 

2.  Short  exposure  gives  brilliance,  vigor,  hardness. 

Now,  turning  to  development,  we  define  normal  as  that 
which  will,  with  a  scientifically  correct  exposure,  give  a  scien- 
tifically perfect  negative.  Again  we  take  "  normal "  as  our 
standard  of  comparison,  and  we  say,  cceteris  paribus  : 

Strong  or  short  development  gives  softness,  harmony, 
effeminacy. 

"Weak  or  long  development  gives  contrast,  vigor,  hardness. 

(There  are,  we  admit,  marked  exceptions  to  these  state- 
ments.) 

Super-normal  pyro  in  development  gives  contrast,  hardness. 

Super-normal  alkali  in  development  gives  detail,  harmony. 

Super-normal  restrainer  in  development  gives  hardnes?, 
want  of  detail. 

(See  chapter  on  development  of  gelatine  bromide  plates,  to 
which  these  remarks  are  intended  to  apply.) 

These  statements  are  all  to  be  taken  as  general. 

By   attending  to  the   above  suggestions  the   reader  may 


THE    PROCESSES    OF    PUKE    PHOTOGRAPHY. 


83 


acquire  a  certain  amount  of  control  over  the  quality  of  his 
negatives  ;  he  may  learn  not  only  how  to  produce  certain 
effects,  but  how  to  avoid  certain  dangers.  If  on  his  subject 
he  find  violent  contrasts  beyond  what  he  wishes  to  portray,  as 
is  often  the  case  in  snow  scenes  and  dark  wooded  glens,  he 
will  get  a  hint  not  to  under-expose  nor  to  use  a  supernormal 
quantity  of  restrainer.  If  he  has  a  wide,  monotonous  expanse 
of  landscape,  he  will  be  warned  not  to  over-expose  nor  to  over- 
dose his  development  with  alkali. 

Where  a  subject  contains  masses  of  shadows  and  masses  of 
high  lights  in  over-violent  contrast,  and  where  there  is  fear  of 
the  lights  being  seriously  over-exposed  while  the  shadows  are 
being,  according  to  the  old  rule,  "looked  after,"  the  cap  of 
the  lens,  or  a  "  flap  shutter,"  may,  with  great  advantage  and 
a  little  practice,  be  used  to  shade  the  light  parts  while  the 
shadows  are  being  exposed. 


CHAPTEK  XIY. 
DEVELOPMENT  OF  GELATINE  BROMIDE  PLATES. 

Alkaline  Pyrogallol  Developer. — In  this  developer  the 
pyrogallol,  pyrogallic  acid,  or  "  pyro,"  is  used  on  account  of 
its  power  of  absorbing  the  oxygen  of  the  water  with  which  it 
is  dissolved,  and  thus  leaving  the  hydrogen  free  to  combine 
with  part  of  the  haloid  silver  salts  iu  the  film.  Hydrochinon, 
another  substance  similarly  used,  acts  on  the  same  lines.  The 
alkali,  always  required  with  the  pyro  developer,  acts  as,  and 
is  called,  the  "  accelerator "  of  the  action  of  the  pyro.  The 
"  restrainer,"  consisting  usually  of  a  soluble  bromide,  is  used 
to  prevent  too  great  rapidity  of  action,  and  to  obviate  the 
danger  of  development  or  fog  in  unexposed  parts  of  the  plate. 
The  action  of  soluble  bromides  as  restrainers  is  a  matter  very 
imperfectly  understood,  and  as  we  have  nothing  to  do  with 
theories  here,  we  confine  ourselves  to  saying  that  the  soluble 
free  bromide  acts  much  more  forcibly  as  a  restraint  upon  the 
portions  not  acted  upon  by  light  than  upon  those  portions  of 
the  film  which  have  received  light  action.  The  larger  the 
dose  of  free  soluble  bromide  the  larger  may  be  the  proportion 
of  the  alkali  without  danger  of  fog. 

As  accelerators,  any  of  the  alkalis  might  be  used  but  for 
certain  inconveniences  not  directly  connected  with  the  process 
of  development.  There  are  but  four  alkalis  commonly  used  : 
Ammonia,  sodic  carbonate,  potassic  carbonate,  and  ammonic 
carbonate.  To  these  we  might  add  hydroxylamine. 

Ammonia. — Aqueous  solution  of  ammonical  gas.  This, 
used  as  an  accelerator,  has  the  advantage  of  great  vigor,  and 
we  claim  that  with  it,  under  suitable  circumstances,  a  negative 
may  be  produced,  perhaps  a  shade  superior  to  the  best  that  can 
be  got  with  any  other  alkali.  But,  unfortunately,  many  plates 


THE    PKOCESSKS    OF    PUKE    PHOTOGRAPHY.  85 

now  on  our  markets,  especially  those  produced  by  the  ammonio- 
nitrate  emulsion  process,  have  a  strong  tendency  to  green  fog 
when  treated  with  the  ammonio-pyro  developer.  And  the 
ammonia  solution  being  very  volatile,  it  is  next  to  impossible 
to  calculate  the  precise  amount  of  ammonia  present  in  any 
quantity  of  the  "  liquor  ammonias  fort.,"  sold  as  such,  and 
stated  to  have  the  specific  gravity  '880.  As  a  matter  of  fact, 
liquor  ammonise  of  so  low  specific  gravity  as  '880  is  extremely 
scarce,  and,  even  if  procured,  would  very  soon  lose  much  of  its 
gas  if  the  bottle  were  opened  a  few  times.  At  specific  gravity 
•880  the  solution  contains  only  40  per  cent,  of  ammonia.  Con- 
sulting the  table  of  Carius  (given  at  the  end  of  this  book),  we 
find  that  at  a  specific  gravity  of  '92  the  liquid  contains  20  per 
cent,  of  gas  ;  so  that  if  we  wish  to  measure  very  accurately  the 
quantity  of  real  ammonia  we  are  to  use,  the  best  plan  is  to 
dilute  whatever  ammonia  liquor  we  have  till  our  specific 
gravity  test  shows  '92,  and  then  to  use  double  the  quantity  we 
shall  give  throughout  our  formulae,  which  are  based  approxi- 
mately on  "  '880  liquor  amrnoniae." 

Sodic  and  Potassic  Carbonates  are  not  volatile,  and  not 
prone  to  produce  green  fog  in '  use ;  however,  they  give  off 
carbonic  acid,  itself  a  restrainer,  so  that  with  these  carbonates, 
and  also  with  amnionic  carbonate,  we  use  less  soluble  bromide 
or  none  at  all.  The  sodic  carbonate  gives  density  par  excel- 
lence, the  potassic  salt,  perhaps,  gives  a  little  extra  detail. 
Carbonate  of  ammonia  (ammonic  carbonate)  is  remarkable  for 
its  power  of  giving  density,  but  it  acts  very  slowly,  and,  both 
as  a  solid  and  in  solution,  it  is  unstable.  Nevertheless,  it 
deserves  more  attention  as  an  alkali  for  development  than  it 
receives,  as  a  rule. 

Increase  of  pyro,  up  to  a  certain  limit,  produces  increased 
density ;  increase  of  accelerator  increases  detail  and  also  den- 
sity, provided  that  the  line  where  fog  begins  is  not  passed. 
Increase  of  restrainer  protracts  the  time  required  for  develop- 
ment, is  apt  to  produce  thinness,  and  to  prevent  detail  from 
appearing  if  the  plate  is  the  least  under-exposed. 

We  are  often  astonished,  and  always  puzzled,  by  the  ridicu- 
lously intricate  formulae  sent  out  by  plate  makers  as  instructions 


86  THE   PEOCES8E8   OF   PUKE   PHOTOGRAPHY. 

for  working  their  plates  to  the  best  advantage.  We  seldom 
dream  of  making  up  stock  solutions  in  the  terms  of  these 
empiric  formulae,  but  we  always  endeavor  to  analyze  the 
formulae  so  as  to  find  out,  as  nearly  as  may  be,  without  a  long 
string  of  "  repeating  decimals,"  how  much  of  each  reagent 
each  formula  contains.  From  this  calculation,  generally 
troublesome,  we  gather  what  are  the  qualities  we  may  expect 
from  the  plates  in  question.* 

There  is  no  virtue  beyond  that  of  convenience  in  ten-per- 
cent, solutions,  but  ten-per-cent.  solutions  will  be  found  to 
answer  all  purposes.  We  shall  state  the  method  of  making 
such  solutions  for  alkaline  developers,  and  thereafter  we  shall 
give  formulae  only  in  terms  of  the  reagents  actually  employed. 

Pyro  Solution,  "  10  per  cent." — If  we  took  an  avoirdupois 
ounce  of  pyro,  dissolved  it  in  water,  and  made  the  bulk  up  to 
nine  fluid  ounces,  we  should  have  approximately  a  10  per  cent, 
solution,  and  every  ten  minims  would  contain  one  grain  of 
pyro.  But  pyro  dissolved  in  this  way  would  oxidize,  and  in 
a  very  short  time  become  useless.  Two  drams  of  citric  acid 
added  would  improve  the  keeping  qualities,  but  we  give  two 
methods  far  superior,  the  first  due  to  the  ingenuity  of  Mr.  H. 
B.  Berkeley,  the  second  a  modification,  by  ourselves,  of  a  form- 
ula first  promulgated  by  Messrs.  Mawson  &  Swan,  "of  New- 
castle, England : 

SULPHO-PYROGALLOL  (BERKELEY.) 

Take 

No.  1.     Sodic  sulphite,  best  obtainable. .  .4  ounces  avoirdupois 
Water,  hot about  6  ounces 

dissolve ;  add  citric  or  sulphurous  acid  till  the  reaction  is  dis- 
tinctly acid.     Add  to  one  commercial    ounce  of   pyro,  dis- 
solve, filter,  make  up  with  water  to  nine  ounces.      Label: 
"  Pyro.     10  per  cent.     10  minims  =  1  grain  pyro." 
Take 

No.  2.     Potassic  bisulphite %  ounce 

Water about  5      ounces 

dissolve,  pour  into  an  ounce  of  pyro,  make  up  to  nine  ounces, 

*  See  the  table  compiled  by  Messrs.  Clarke  and  Ferrero. 


THE    PROCESSES    OF    PURE    PHOTOGRAPHY.  87 

filter.  Label :  "  Pyro.  10  per  cent.  10  minims  =  1  grain." 
(Messrs.  Mawson  &  Swan  formulate  "  Meta-bisulphite  of 
Potash."  We  know  nothing  about  this  salt,  which  is  not 
listed  by  any  manufacturer  we  know,  except  the  above  firm ; 
we  have  used  the  meta-bisulphite,  and  also  ordinary  bisulphite, 
and  can  distinguish  no  difference  in  the  result.) 

BROMIDE  SOLUTION.     10  PER  CENT. 
Take 

Potassic  or  ammonic  bromide 1  ounce  avoirdupois 

Water about  7  ounces 

dissolve,  make  up  to  nine  ounces.  Label :  "  Bromide.  10  per 
cent.  10  minims  =  1  grain." 

AMMONIA  SOLUTION.     10  PER  CENT. 
Take 

Liq.  ammonia,  .880 % 1  fluid  ounce 

Water 9  fluid  ounces 

Label :  "  Ammonia.  10  per  cent.  10  minims  =  1  minim  Hq. 
ammonia,  .880." 

Make,  in  the  same  manner  as  the  bromide  solution,  10  per 
cent,  solutions  of  sodic  and  potassic  carb.,  or  proceed  as  fol- 
lows, ±or»a  solution  which  can  be  recommended  : 

Take 

Sodic  carb.  crystals  not  "anhydrous". .%  ounce  avoirdupois 
Potassic  carb ^y%  ounce  avoirdupois 

dissolve  in  water,  and  make  up  to  nine  ounces.  Label :  "  Car- 
bonates. 10  per  cent.  10  minims  =  \  grain  sod.  and  £  grain 
pot.  carb." 

A  normal  developer  may  be  thus : 

1.   Pyro 2  grains 

Ammonia 2  minims 

Bromide 1  grain 

Water  to. . .  . .   1  ounce 


Or, 


2.   Pyro 3  grains 

Sodic  carbonate 12  grains 

Water  to. .  .  . .   1  ounce 


88  THE    PKOCE8SE8    OF   PUKE   PHOTOGRAPHY. 

Or, 

3.  Pyro 4grains 

Potassic  carbonate 20  grains 

Water  to 1  ounce 

Or, 

4.  Pyro 4  grains 

Potassic  and  sodic  carbonates 16  grains 

Water  to 1  ounce 

To  each  of  the  developers  (2,  3,  and  4)  may  be  added,  if 
there  is  the  least  fear  of  over-exposure,  one-half  grain  of 
bromide,  but  it  must  be  remembered  that  with  the  carbonate 
developers  the  restraining  action  of  bromide  appears  dispro- 
portionately vigorous. 

These  are  by  no  means  the  limits  in  either  direction  of  our 
use  of  the  accelerators,  nor  are  we  restricted  to  any  particular 
time  for  duration  of  development.  The  carbonate  developers 
in  particular  will  go  on  acting  for  a  very  long  time,  but,  as  a 
rule,  the  action  of  the  ammonia  developer  is  sooner  exhausted, 
and  a  little  more  ammonia  may  be  added,  the  quantity  vary- 
ing with  the  requirements  of  the  case  and  the  capability  of 
the  plate  for  tolerating  ammonia.  If  bromide  be  also  added, 
a  very  considerable  quantity  of  ammonia  is  permissible.  It 
may  be  said  that  the  above  developers  ought  to  fully  develop 
a  plate  properly  exposed  in  three  minutes,  but  in  the  case  of 
of  ammonia  a  perfect  negative  may  result  even  if  we  require 
to  add  another  minim  or  two  of  ammonia  to  each  ounce  of 
developer. 

Soluble  bromide,  as  we  have  said,  has  a  strong  tendency  to 
prevent  density,  and  where,  on  this  or  any  other  account,  the 
use  of  a  large  quantity  of  soluble  bromide  is  contra-indicated, 
use  may  be  made  of  citrates,  as  first  pointed  out  by,  we 
believe,  Mr.  G.  W.  Webster.  The  citrates  may  be  made  up 
in  10  per  cent,  solutions,  thus  : 

Sodic  or  potassic  citrate 1  ounce,  avoirdupois 

Dissolve  in 

Water  and  make  up  to 9  ounces 


THE    PROCESSES    OF   PURE    PHOTOGRAPHY.  89 

As  there  is  some  doubt  as  to  which  citrate  is  the  better,  we 
use  both  : 

Sodic  citrate J£  ounce,  avoirdupois 

Potassic  citrate J£  ounce,  avoirdupois 

Water  to 9  ounces 

For  cases  of  very  great  over-exposure,  four  grains  of  citrate 
may  be  used  for  each  minim  of  ammonia  in  the  developer, 
but,  as  a  rule,  two  grains  will  be  found  sufficient.  The  citrate, 
combining  with  the  ammonia  to  form  ammonic  citrate,  allows 
density  to  increase,  but  prevents  the  appearance  of  further 
details. 

For  cases  of  over-exposure  we  decrease  the  alkali,  increase 
the  bromide  and  the  pyro.  With  the  carbonates  the  addition 
of  water  frequently  has  the  desired  effect.  For  gross  over- 
exposure,  whether  known  before  development,  or  discovered 
after  development  is  started  (see  below),  the  citrates  may  be 
used  with  ammonia. 

Under-exposure,  if  it  can  be  met  at  all,  will  be  met  by  re- 
ducing the  pyro  and  bromide,  and  increasing  the  alkali  and  the 
water  where  there  is  fear  of  over-density. 

Subjects  presenting  violent  contrasts  of  light  and  shade,  as 
interiors,  dark  glens,  etc.,  will  be  developed  into  the  best  nega- 
tives, if  the  exposure  has  been  full,  by  considerably  reducing 
the  pyro  and  bromide,  increasing  the  alkali,  as  far  as  is  safe, 
and  developing  lightly,  that  is,  not  carrying  the  developing 
action  so  far  as  for  a  normal  subject. 

Subjects  monotonous,  or  devoid  of  contrast,  may  be  treated 
with  an  extra  dose  of  pyro  and  bromide,  just  enough  alkali  to 
secure  detail,  and  a  development  carried  to  a  super-normal 
degree. 

The  variations  that  can  be  made  in  alkaline  pyrogallic  develop- 
ment are  simply  innumerable;  in  fact,  its  "elasticity"  is  its 
strong  point  of  advantage  over  the  "ferrous  oxalate."  (See 
lower.)  The  ferrous  oxalate  has  a  certain  amount  of  range 
also,  but  in  this  matter  it  is  distinctly  inferior  to  the  alkaline 
process. 

When  the  worker  is  undecided  as  to  whether  his  exposure 
has  been  approximately  correct  or  not,  the  simple  and  evident 


90  THE   PROCESSES   OF   PURE   PHOTOGRAPHY. 

plan  is  to  develop  slowly  at  first  till  the  quality  of  the  image 
slowly  growing  can  be  examined.  For  this  purpose  the  normal 
developer  may  be  made  up,  but  with  only  one  half  of  the 
alkali,  the  other  half  being  kept  apart  till  the  image  either  re- 
fuses to  appear,  or  appears  over-exposed,  as  will  presently  be 
explained.  Or  two  complete  but  totally  different  solutions 
may  be  prepared,  one  strong  in  restraining,  the  other  in  accel- 
erating, reagents.  Thus,  No.  1  may  contain  :  pyro,  4  grains ; 
bromide,  3  grains;  ammonia,  2  minims  to  each  ounce;  and 
No.  2  may  contain  :  pyro,  1  grain ;  bromide,  1  grain ;  ammonia, 
4  minims.  The  plate  is  treated  with  No.  1  first ;  if  no  image 
appear,  and  if  it  is  not  hopelessly  under-exposed,  No.  2  will 
probably  put  it  right,  if  it  is  over-exposed  No.  1  will  probably 
save  it,  if  anything  can,  or  citrate  may  be  added  when  the 
details  are  all  visible ;  or  if  in  No.  2  details  begin  to  appear 
too  quickly,  we  can  put  the  plate  back  into  No.  1  till  density 
is  gained. 

As  plate  after  plate  is  sometimes,  for  economy's  sake, 
developed  in  the  same  solution,  we  must  point  out  that  in  such 
cases  not  only  is  the  pyro  oxidized,  and  rendered  inert,  but 
fresh  bromide  is  formed,  and  also  the  ammonia  decreased  by 
the  action  between  the  liberated  bromine  and  the  ammonia, 
ammonia  bromide  being,  in  fact,  formed,  or  sodic,  or  potassic 
bromide,  as  the  case  may  be. 

The  Hydrochinon  Developer  was  introduced  some  years  ago, 
by  Captain  Abney,  but  for  some  time  fell  into  disuse ;  it  appears 
to  be  once  more  attracting  notice.  The  substance,  hydrochinon, 
does  not  keep  well  (Eder),  and  in  our  experience  does  not,  as 
a  developer,  work  well  with  ammonia.  But  with  a  carbonate 
it  will,  when  fresh,  be  found  to  give  fine  results.  We  give 
the  formula  of  the  discoverer,  and  in  a  later  chapter  will  be 
found  another  method  of  using  it  for  another  purpose. 

1.  Hydrochinon 10  grains 

Water 10  ounces 

2.  Carbonate  of  potash,  a  saturated  solution,  in  water. 

To  each  ounce  of  No.  1  is  added  1  dram  of  No.  2,  and  about 
10  drops  of  10  grains  to  the  ounce  solution  of  chloride  of 
sodium  (common  salt.) 


THE    PROCESSES    OF    PUKE    PHOTOGRAPHY.  91 

Possibly  some  workers  may  prefer  to  keep  their  carbonates 
and  citrates  in  more  concentrated  solutions  than  the  10  per 
cent.  we  have  suggested.     To  make  a  30  per  cent,  solution  of 
carbonates,  for  instance : 
Take 

Sodic  carb H  ounce  avoirdupois 

Potassic  carb   1^  ounce  avoirdupois 

Water  to 9  ounces. 

Label :  "  Carb.  Solution,  30  per  cent. — 10  minims  =  3  grains 
carbs." 

By  way  of  example  o«f  the  use  of  these  10  per  cent,  and 
30  per  cent,  solutions,  let  us  suppose  we  wish  to  make  two 
normal  developers  as  above  in  quantities  of  3  ounces  each. 

For  our  so-called  Normal  Ammonia  Developer,  No.  1  (page 
87)  take: 

10  per  cent,  pyro 60  minims 

10  per  cent,  ammonia  . . 60 .minims 

10  per  cent,  bromide 30  minims 

Water  to .     3  ounces 

For  a  normal,  such  as  No.  4  (page  88) : 

10  per  cent,   pyro 120  minims  (=  2  drams) 

10  per  cent,  carbs 480  minims  (=  1  ounce) 

or  :  30  per  cent,  carbs 160  minims  (=  2  drains  40  minims) 

Water  to 3  ounces 

If  to  the  former  we  wish  to  add  1  drop  of  ammonia  per 
ounce  of  developer,  then  add 

10  per  cent,  ammonia 3x10  =  30  minims 

The  Ferrous  Oxalate  Developer,  largely  used  on  the  Euro- 
pean continent  on  account,  perhaps,  of  the  quick-printing 
quality  of  the  negatives  produced.  Ferrous  oxalate  is  a  yellow 
salt  insoluble  in  water,  but  soluble  in  potassic  oxalate.  By 
mixing  ferrous  sulphate  with  potassic  oxalate  we  not  only  form 
ferrous  oxalate,  but  hold  it  in  solution  by  the  excess  of  potassic 
oxalate. 
Take 

1.   Potassic  oxalate 1  part 

Water,  hot 3  parts 


92  THE    PROCESSES   OF   PURE    PHOTOGRAPHY. 

The  oxalate  should  be  acidified  with  oxalic  acid.    The  water 
should  be  free  from  lime. 
Take 

2.  Ferrous  sulphate  (protosulphate  of  iron). 1  part 

Water,  hot 4  parts 

Acidify  with  sulphuric  acid. 

To  make  the  developer :  Pour  one  part  of  No.  2  into  four 
parts  of  No.  1.  Do  not  pour  No.  1  into  No.  2.  A  little  bromide 
(say  half  a  grain  per  ounce  of  the  above  mixture)  may  be 
added  in  case  of  known  over-exposure ;  but  it  is  not  necessary 
nor,  indeed,  advisable  in  ordinary  cases.  This  developer,  also, 
may  be  varied  within  limits,  and  the  best  way  to  get  "  latitude  " 
of  working  with  it  is  to  make  several  mixtures  of  various  pro- 
portions, as  No.  2  one  part,  to  No.  1  five  parts ;  or,  No.  2  one 
part,  to  No.  1  six  parts  ;  and  to  begin  development  with  the 
weakest,  passing  the  plate  to  the  stronger  solutions  as,  and  if, 
desired.  A  trace  of  sodic  hyposulphite  added  to  this  solution 
of  ferrous  oxalate  increases  its  developing  activity,  but  this 
must  be  added  with  great  caution,  as  it  often  results  in  catas- 
trophe to  the  negative. 

This  developer,  once  mixed,  may  be  used  over  and  over 
again  so  long  as  it  is  used  within  a  certain  time  after  the  mix- 
ture of  the  two  solutions.     The  mixture,  however, 
may  be  long  preserved  by  keeping  it  under  a  layer 
of  oil,  as  may  be  done  by  the  device  figured  here. 
The  mixed  developer  is  poured  in  at  the  top,  oil 
is  poured  on  top  of  it,  the  cork  is  replaced  till 
developer  is  required,  when  the  cork  (and  with  it 
the  end  of  the  rubber  tube)^  is  lowered  over  a 
dish,  and  the  developing  liquid,  of  course,  pours 
out.     Sometimes,  in  order  to  maintain  the  vigor 
of    this    developer,   bright  iron   wire     is    kept    in    contact 
with  it. 

Manipulations  of  Development.— The  exposed  plate  being 
removed  from  the  dark  slide  in  the  dark-room,  should  be 
dusted  with  a  broad  earners-hairbrush  and  laid  face  upwards  in 
a  black  developing-dish,  such  as  described  in  our  chapter  on 
apparatus. 


THE    PROCESS KS    OF    PURE    PHOTOGRAPHY.  93 

The  developing  solution  is  then  swept  over  the  film  in  such 
a  way  as  to  cover  every  part  at  the  first  sweep.  Plenty  of 
solution  should  be  allowed  by  the  beginner,  in  order  to  prevent 
any  part  of  the  film  being  missed  by  the  first  wave  of  the 
developer,  and  so  uneven  markings  being  produced  ;  the  solu- 
tion is  to  be  kept  moving  over  the  film. 

In  a  period  varying  from  ten  seconds  to  twenty-five  or 
thirty,  in  a  general  way,  the  image  may  be  expected  to  put  in 
an  appearance.  The  period  varies  considerably,  and  depends 
on  the  quality  of  gelatine  used  in  the  emulsion  chiefly,  but,  of 
course,  this  refers  to  "  normal "  exposure  and  developer.  If 
the  exposure  or  developer  be  far  wide  of  the  normal,  it  is  im- 
possible to  say  how  long  or  how  short  a  time  the  image  may 
take  before  it  appears.  The  first  appearance  of  the  image 
under  the  action  of  a  normal  developer  ought  to  be  most  care- 
fully scrutinized.  We  consider  this  appearance  by  far  the 
best  guide  to  the  future  regulation  of  the  developing  process. 

If  the  image  comes  up  very  gradually,  almost  reluctantly, 
one  detail  following  another  with  a  considerable  lagging  in 
the  progress,  the  exposure  has  probably  been  insufficient.  The 
negative,  however,  may  be  saved  by  an  addition  of  alkali,  and, 
perhaps,  of  water ;  or,  the  developer  may  be  rejected,  the 
plate  washed,  and  a  new  developer  made  up  containing  less 
restrainer  and  more  accelerator,  in  certain  cases  with  less  pyro. 

If,  on  the  other  hand,  the  high-lights  are  instantly  followed 
by  half-tones,  and  a  gray  color  appears  over  the  whole  film,  the 
plate  has  certainly  been  over-exposed.  An  over-exposed  plate, 
taken  in  time,  may  almost  always  be  saved,  unless  the  over- 
exposure  is  very  gross.  In  bad  cases  of  over-exposure  the 
developer  should  be  instantly  rejected,  the  plate  washed,  and 
a  new  developer  made  up,  containing  more  restrainer  and  pyro, 
and  less  accelerator. 

If,  after  the  application  of  this,  the  image  still  comes  up 
very  gray,  it  is  well  to  allow  the  details  to  appear  in  their 
entirety,  and  then  to  add  to  the  developer  a  dose  of  the  citrate 
solution,  recommended  in  the  proportion  of  from  two  to  four 
grains  of  citrate  to  each  minim  of  ammonia.  If  a  carbonate 
developer  is  being  used,  the  developer  may  be  instantly  watered 


94  THE   PROCESSES    OF    PUKE    PHOTOGRAPHY. 

on  the  appearance  of  the  grayness  ;  and  if  that  is  not  sufficient 
to  allow  the  high-lights  to  gain  density,  a  dose  of  bromide  may 
be  added. 

With  a  normal  developer,  such  as  any  of  those  we  have 
given,  the  image,  in  a  case  of  proper  exposure,  will  begin  to 
appear  in  from  ten  to  thirty  seconds,  the  high-lights  will  appear 
first,  but  before  they  have  acquired  any  considerable  density, 
the  half-tones  will  appear,  followed  in  turn  by  the  shadows. 
The  whole  process  of  revelation  will  be  gradual,  steady,  un- 
halting.  When  the  density  appears  sufficient,  and  when  no 
longer  any  white,  and  not  much  gray,  is  seen  on  the  face,  the 
plate  may  be  examined  by  transmitted  light,  and  the  back  may 
also  be  examined,  so  that  the  operator  may  note  to  what  extent 
the  action  of  the  developer  has  penetrated  the  film.  The  back 
of  the  plate  is  no  real  criterion  of  anything,  except  the  quality 
of  the  emulsion  and  the  method  of  coating  and  setting  the 
plate.  Combined  with  examination  of  the  image  by  reflected 
and  transmitted  light,  examination  of  the  back  of  the  plate  may 
be  of  service  when  the  worker  knows  the  qualities  of  his 
batch  of  plates.  Experience  alone  can  teach  to  what  point  a 
plate  should  be  developed. 

If,  in  any  particular  part,  details  appear  reluctant  to  appear, 
the  developer  may  be  repeatedly  poured  upon  that  part  from 
the  cup  or  measure,  or  a  camel's-hair  brush  may  be  well  wetted 
with  the  developer  and  rubbed  over  the  weak  part.  We  have 
even  dipped  the  brush  in  stronger  developer  in  a  separate  ves- 
sel, and  with  it  "locally  developed"  details. 

When  the  development  is  judged  complete,  the  plate  is  well 
washed  under  the  tap,  and  either  fixed  at  once,  or  placed  in  a 
strong  solution  of  common  alum,  and  fixed  after  washing.  The 
object  of  the  alum  is  to  harden  the  gelatine,  and  prevent  pos- 
sible blistering,  or  frilling,  in  later  operations.  For  the  alum 
bath  before  fixing  no  acid  should  be  used,  except  after  ferrous 
oxalate,  when  a  small  quantity  of  citric,  or  acetic,  acid  may  be 
added,  though  we  do  not  insist  on  it.  If  there  are  grounds  for 
expecting  frilling,  the  plate,  after  pyro  development,  may  be 
put  into  a  slightly  acid  alum  solution,  straight  from  the  devel- 
oper;  in  this  case  the  acid  is  of  use  in  arresting  develop- 


THE  PROCESSES  OF  PUKE  PHOTOGRAPHY. 


95 


ment.  As  a  rule,  it  will  be  found  advisable  not  to  alum  be- 
fore fixing,  as  after  fixing  the  negative  may  be  of  such  a  quality 
as  to  be  better  unalumed,  «'.  £.,  the  negative  may  be  slightly 
thin  for  printing  purposes,  and  the  stain  which  the  alum  is 
partly  used  to  remove  might  be  advantageous  to  such  a 
negative. 


CHAPTER   XV. 

GELATINE   BROMIDE   PLATES,   FIXING,  INTENSIFI- 
CATION, REDUCTION,  ETC. 

THE  fixing  solution  is  as  follows  : 

Sodic  hyposulphite 5  ounces 

Water 1  pint 

Ammonia,  or  ammonic  carbonate  till  the  solution  is  dis- 
tinctly alkaline.  And  it  must  always  be  kept  alkaline  and  up 
to  strength.  After  the  plate  has  been  in  the  fixing  solution 
for  a  certain  time,  the  white  (unaltered  salts)  will  disappear 
from  the  back  of  the  plate ;  the  plate  is  at  that  stage  just 
half  fixed,  and  must  be  left  about  as  long  again  to  insure 
proper  fixing.  If,  after  a  negative  has  been  kept  for  some 
time,  and,  perhaps,  printed  from  a  good  many  times,  a  yellow- 
brown  discoloration  appears  upon  it,  usually  starting  at  or 
near  one  edge,  that  plate  was  only  half  fixed,  and  it  is  to  be 
regretted  that  this  matter  is  so  frequently  overlooked  as  it  is. 

After  fixation  is  complete  the  negative  has  to  be  thoroughly 
washed,  and  with  a  glass  negative  this  is  not  always  so  simple 
an  operation  as  might  be  expected.  The  plates  may  be  washed 
in  about  ten  minutes  by  causing  a  good  rose  tap  to  play  on 
each,  but  this  is  not  always  convenient,  so  they  are  either  to 
be  soaked  for  some  hours  face  downwards  in  a  suitable  vessel, 
the  water  being  frequently  changed,  or  they  may  be  washed, 
a  good  number  at  a  time,  in  running  water  by  the  aid  of  an 
article  figured  Nos.  23  and  23«. 

There  are  a  great  many  apparatus  on  the  market  for  wash- 
ing glass  negatives,  most  of  them  on  the  syphon  principle  ;  as 
a  rule,  these  are  good. 

The  washing  after  fixing  need  not,  in  its  first  stage,  be  so 


THE   PROCESSES    OF    PURE    PHOTOGRAPHY.  97 

very  prolonged  if  the  alum  and  acid  bath  is  to  be  used.  But 
the  negative  should  be  well  washed  and  not  merely  rinsed 
before  it  is  immersed  in  the  following  bath,  which  may  be 
omitted  if  the  plate  was  immersed  for  a  considerable  time  in 
alum  solution  before  fixing  : 

Potash  alum,  solution  saturated  in  cold  water. 

Citric  acid,  to  each  pint  of  the  above,  three  ounces ;  or  this 
also  may  be  saturated  in  the  alum  solution. 

Or  hydrochloric  acid  to  each  pint  of  the  above  double 
saturated  solution,  half  an  ounce. 

This  bath  will  harden  the  gelatine  and  will  remove  any 
stain  due  to  the  pyro  used  in  development. 

After  again  washing,  the  plates  are  allowed  to  dry ;  heat 
must  not  be  used  to  hurry  the  drying.  If  it  is  required  to 
dry  a  plate  in  a  hurry,  soak  it  five  minutes  in  good  alcohol, 
take  it  out  of  the  dish  and,  holding  it  tightly  in  the  hand, 
whirl  it  rapidly  or  wave  it  quickly  through  the  air.  If  frill- 
ing makes  its  appearance  during  the  last  washing,  at  once 
cease  washing  and  plunge  the  plate  into  alcohol,  leaving  it 
there,  till  the  frilling  disappears,  which  may  take  many  hours. 
If  a  batch  of  plates  shows  a  tendency  to  frilling,  alum  each 
plate  well  before  fixing,  and  after  fixing  put  a  good  dose  of 
common  salt  into  a  dish  with  water  and  immerse  in  it  each 
plate  as  it  leaves  the  fixer.  If  the  plates  frill  in  spite  of  these 
precautions  send  them  back  to  the  maker,  they  are  not  reason- 
ably adapted  for  the  purpose  for  which  they  were  bought,  or 
for  which  they  were  sold. 

After  drying,  the  negative  may  or  may  not  be  varnished. 
The  gelatine  film  is  quite  strong  enough  to  stand  the  ordinary 
wear  of  an  amateur's  printing;  but  if  there  is  fear  of  damp, 
or  of  scratches,  or  if  a  great  number  of  prints  are  likely  to  be 
required,  the  negatives  may  be  varnished  in  the  manner  given 
for  collodion  negatives.  A  film  of  plain  collodion  over  the 
gelatine  is  a  good  preservative,  and  may  be  followed  by  a 
film  of  varnish.  Among  our  formulae  at  the  end  will  be 
found  one  for  varnish. 

Intensifying  gelatine  bromide  negatives  is  in  most  hands  a 
very  uncertain  and  dangerous  operation  ;  but  if  the  precautions 


9b  THE    PROCESSES    OF    PURE    PHOTOGRAPHY. 

we  shall  point  out  are  duly  attended  to,  there  ought  to  be  no 
difficulty.  Still,  it  is  much  better  to  make  negatives  such  as  are 
certain  not  to  require  intensification,  especially  as  reduction  is 
an  operation  much  more  simple,  safe,  and  certain,  than  intensi- 
fication. 

There  must,  in  the  first  place,  be  not  a  trace  of  hypo  left  in 
the  film  ;  if  any  hypo  remain,  the  negative  will  be  ruined,  to 
a  certainty.  Various  hypo-eliminators  are  suggested  and  recom- 
mended, chiefly  depending  on  the  action  of  chlorine  in  one 
shape  or  other.  We  cannot  advise,  the  use  of  any  hypo-elim- 
inator except  water ;  some  of  the  advertised  articles  eliminate 
the  hypo,  certainly,  but  introduce  something  worse  than  what 
they  eliminate.  Chlorine,  at  all  events,  should  be  avoided. 

MERCURY  INTENSIFIER. 

Mercuric  chloride 1  part 

Water 20  parts 

Of  this,  one  pint.  Strong  hydrochloric  acid,  30  minims. 
(Due  to  Mr.  Arnold  Spiller.) 

In  this  the  plate  is  soaked  till  the  image  becomes  a  pearly 
white  or  bright  gray  color.  Wash  thoroughly.  Put  the  plate 
into  a  dish,  and  sweep  over  it  sufficient  of 

Ammonia 1  part 

Water 20  parts 

Or, 

Sodic  sulphite 1  ounce 

Water 1  pint 

The  former  solution  gives  more  density  than  the  latter,  but 
the  color  of  the  image  produced  by  the  latter  is  better.  If 
sufficient  density  be  not  gained  by  the  first  operations,  they 
can  be  repeated,  beginning  with  the  mercury,  washing  and 
finishing  with  the  sulphite.  The  washing  after  intensification 
must  be  thorough. 

Reduction  of  Gelatine  Bromide  Negatives. — If  a  fixed  and 
washed  negative  be  found  too  dense,  it  may  be  reduced  in  the 
following  simple  manner,  suggested  by  Mr.  E.  Howard  Far- 
mer, of  London,  England. 


THE    PROCESSES   OF    PURE   PHOTOGRAPHY.  9<> 

Make  a  fresh  solution  of  sodic  hyposulphite,  as  for  the 
fixing-bath,  but  omit  the  alkali.  Make  also  a  strong  solution 
of  potassic  ferricyanide  ("  red  prussiate  of  potash.")  Place 
the  negative  in  the  hypo  for  some  minutes,  and  put  into  a  cup 
or  measure  a  few  drops  of  the  ferricyanide  solution.  Pour 
the  hypo  into  the  measure  with  the  ferricyanide,  so  as  to  mix 
the  two  well,  and  then  pour  the  mixture  on  the  negative  in  the 
dish.  Immediately  a  reducing  action  will  begin,  and  the  first 
dose  may  be  sufficient;  if  the  action  ceases  before  sufficient 
reduction  has  taken  place,  add  a  little  more  ferricyanide,  as 
before. 

"  Local "  reduction,  i.  e.t  reduction  of  parts  only  of  a  nega- 
tive, may  be  easily  performed  by  rubbing  the  parts  with  a  rag, 
dipped  in  alcohol.  The  rubbing  must  be  fairly  vigorous  and 
prolonged ;  but  care  must  be  taken  not  to  break  the  film  by 
over-rubbing,  nor  by  allowing  any  grit  to  get  between  film 
and  rag. 


CHAPTEE  XYI. 
DEFECTS    IN    GELATINE-BROMIDE    NEGATIVE. 

THE  gelatine-bromide  process  is,  like  all  other  processes 
involving  delicate  manipulation  (especially  in  semi-darkness) 
and  accurate  chemical  calculations,  liable  to  defects,  and  some- 
times a  worker  will  produce  a  defect  altogether  peculiar  to  his 
own  manner  of  working  and  unintelligible  to  others.  All  that 
can  be  done  in  this  chapter  is  to  deal  with  the  defects  that 
anyone  may  fall  upon,  and  that  the  writers  have  themselves 
experienced  and  seen. 

Fog  may  be  due  to  many  causes.  It  is  not  difficult  to  recog- 
nize, and  hardly  needs  description,  but  we  may  liken  it  to  a 
general  veil,  of  more  or  less  pronounced  character,  all  over  the 
plate.  There  are  two  kinds  of  fog,  distinct  in  nature,  appear- 
ance, and  rationale.  Green  fog  is,  unfortunately,  common  in 
commercial  plates  kept  for  any  considerable  time,  and  is 
noticed  first  in  the  shadows  of  a  negative  as  seen  from  the 
back  of  the  plate.  In  this  shape  it  does  very  little  harm  ;  but 
what  we  take  to  be  a  variety  of  the  same  fog  shows  itself  as  a 
bronzing,  spotty,  metallic-looking  stain,  which  usually  begins 
at  the  edges  of  a  plate  and  creeps  inward,  finally  culminating 
in  red  fog,  which  is  a  hopeless  calamity  to  the  plate.  We 
have  watched  the  progress  of  this  fog  from  the  inchoate 
"  shadow-fog,"  through  the  "  bronze-period  "  "into  the  region 
of  eternal  night."  Ammonia  aggravates  it,  and  in  our  opinion 
causes  it ;  and  plates  showing  a  tendency  to  green  fog  should 
be  developed  with  carbonates  or  ferrous  oxalate.  Plates  even 
above  suspicion  of  this  fog,  when  they  are  new,  often  acquire 
it  if  kept  in  an  atmosphere  where  much  carburetted  hydrogen 
gas  is  burned.  Sometimes,  indeed  frequently,  the  green  fog 
which  appears  to  be  on  the  surface  of  the  film,  can  be  removed 
by  rubbing  the  film  with  a  rag  dipped  in  spirits.  So  far  as 


THE    PEOCESSES    OF    PUKE    PHOTOGRAPHY.  101 

we  know,  Mr.  R.  W.  Robinson  first  brought  this  cure  under 
our  notice.  Red  fog  we  have  never  been  able  to  cure  or  even 
to  mitigate.  We  believe  it  is  merely  an  exaggerated  form  of 
green  fog.  In  emulsion-making,  red  fog  may  be  caused  by 
the  boiling  process  in  presence  of  alkali  ;  such  red  fog  may  be 
"  separated  "  by  the  action  of  "  centrifugal  force  "  (see  page  64), 
which  makes  it  probable  that  this  fog  is  due  to  some  gelatine 
combination. 

Grey  fog  may  arise  from  over-exposure — the  cure  is  evi- 
dent, or  rather,  the  means  of  prevention  ;  unsafe  light  in  the 
developing-rooin,  camera  or  dark-room ,  slide  not  light-tight; 
reflections  inside  camera  or  lens-tube.  All  these  can  be  readily 
discovered  and  remedied.  Fog  may  be  produced  by  too  long 
a  time  being  employed  for  the  drying  of  plates  after  coating 
with  emulsion,  the  danger  or  defect  being  aggravated  in  pro- 
portion as  the  drying  atmosphere  is  damp  or  contaminated 
with  carburetted  hydrogen  or  sulphurous  fumes. 

To  discover  for  certain  whether  the  light  of  the  operating- 
room  is  at  fault,  one  of  the  plates  may  be  exposed  to  the  light 
suspected,  for  five  minutes,  in  contact  with  a  negative  or"  the 
screen  of  a  "  sensitizer."  If  no  image  appear  on  subsequent 
development,  the  light  is  "  safe."  We  have  already  given  a 
method  for  testing  the  camera,  etc.,  for  light-tightness.  An- 
other method  is  to  place  a  plate  in  the  camera  in  the  dark-slide 
as  usual,  and  to  draw  the  shutter,  leaving  the  cap  on  the  lens. 
The  whole  is  allowed  to  stand  in  bright  light  for  a  few 
minutes.  On  development,  fog  will  show  if  due  to  leak- 
age in  the  camera,  or  reflections  arising  therefrom. 

Fog  may  be  due  to  development,  to  overdose  of  alkali  in 
pyro  development,  or  to  alkaline  reaction  in  ferrous  oxalate 
development. 

Over-density  of  the  negative  may  be  due  to  over-develop- 
ment, pure  and  simple,  or  to  over-forcing  in  development 
of  an  under-exposed  plate.  In  the  former  case  the  cure  will 
be  found  in  the  method  of  "  reduction "  given  on  page  99. 
The  other  defect,  where  the  high  lights  are  dense  out  of  pro- 
portion with  the  shadows,  is  difficult,  if  not  impossible,  to 
remedy. 


102  THE    PROCESSES    OF    PUKE    PHOTOGRAPHY. 

Thinness,  or  want  of  density,  may  be  due  to  several  causes. 
Tinder-development ;  intensification  will  be  found  more  easy 
in  this  kind  of  case  than  in  any  other.  Over-exposure;  in- 
tensification may  be  resorted  to.  Light  fog,  in  quantity  not 
sufficient  to  entirely  ruin  the  plate,  will  produce  a  thin  image ; 
thus  a  very  dim  reflection  in  the  camera,  or  a  moderately 
unsafe  light  in  the  operating-room,  while  not  sufficient  to  pro- 
duce a  regular  fog,  will  produce  a  thin  image.  Thinness  may 
be  due  to  the  emulsion.  If  the  plate  is  too  thinly  coated ;  if 
the  emulsion  does  not  contain  sufficient  of  the  silver  haloid  ;  if 
the  emulsion  has  an  over-acid,  or  a  very  alkaline  reaction ;  if 
too  much  chrome  alum  be  used  in  the  emulsion,  and  under 
many  other  less  common  conditions,  a  thin  image  may  result. 

Frilling  may  be  due  to  dirty  plates;  plates  overheated 
before  coating;  an  improper  quality  of  gelatine,  or  want 
of  alum  in  the  gelatine  in  very  warm  weather;  osmotic 
action  in  the  hypo,  produced  usually  by  a  too  strong  solution 
of  hypo ;  action  of  too  strong  acids  on  the  film  at  some  stage, 
as  in  the  alum  bath.  Sometimes  plates  will  frill  in  spite  of 
all  that  can  be  done  to  prevent  it,  but  in  commercial  pro- 
ducts frilling  is  now  happily  very  rare. 

Yellow  Stain  all  over  the  plate,  due  to  the  pyro,  and  occur- 
ing  especially  with  the  carbonate  developers.  The  alum  and 
acid  bath  will  remove  this  stain. 

Spots. — Small  transparent  spots  on  the  negative  are  usually 
due  to  dust.  Opaque  spots  may  arise  from  the  quality  of  the 
gelatine ;  we  have  known  immense  crops  of  them  produced 
by  iron  rust  in  the  water  supply.  Circular  transparent  spots, 
with  sharp  outline,  are  due  to  air-bubbles  forming  in  develop- 
ment, or  in  the  emulsion.  (See  our  instructions  for  applying 
the  developer.)  A  broad  camePs-hair  brush  may  be  used  to 
spread  the  developer  over  the  film  in  the  developing  dish  im- 
mediately after  the  first  application  of  the  developing  solution. 
Some  workers  soak  their  plates  in  plain  water  before  develop- 
ment, there  is  no  harm  in,  nor  need  for,  this  operation  with 
glass  plates. 

Halation  (appearance  of  "halo."  ) — Found  when  objects  in 


THE    PROCESSES    OF   PURE    PHOTOGRAPHY.  103 

high  light  and  objects  in  deep  shadow  are  close  to  each  other 
in  the  picture,  the  most  frequent  examples  being  the  windows 
in  interiors,  and  branches  of  trees  against  a  brilliant  sky. 
Halation  is  due  to  two  causes,  which  must  not  be  confounded. 
1st.  Reflection  from  the  back  of  the  glass  plate,  at  an  angle 
near  to  that  of  "  total  reflection."  This  kind  of  halation  may 
be  obviated  by  using  films  in  place  of  glass  plates,  and  to  a 
certain  extent  by  "backing"  the  glass  plates  with  some  sub- 
stances of  non-actinic  color  in  optical  contact  with  the  glass. 
Burnt  sienna,  rubbed  into  a  paste  with  gum  and  water,  may 
be  applied  to  the  back  of  the  plate  before  exposure,  and 
removed  with  a  sponge  before  development,  or  a  piece  of 
black  "  carbon  tissue  "  may  be  wetted  and  squeegeed  into  con- 
tact with  the  back  of  the  plate.  A  thin  film  of  emulsion, 
especially  in  the  absence  of  the  yellow  stain  due  to  iodide,  is 
very  apt  to  give  halation.  The  defect  may,  to  some  extent, 
be  removed  by  rubbing  with  a  rag  dipped  in  alcohol.  (See 
page  100.) 

2d.  Halation  due  to  dust  in  tTie  air.  This  is,  of  course,  not 
true  halation,  in  the  technical  acceptation  of  the  word,  but  it 
is  often  mistaken  for  the  true  halation.  Neither  the  use  of  a 
film  nor  "backing"  will  prevent  this  kind  of  halation,  but  the 
same  cure  may  be  tried,  viz. :  rubbing  down  the  over-dense 
parts  with  alcohol  on  a  rag. 

Various  curious  markings  may  be  produced  by  various  blun- 
ders. Scummy  marks  are  over-produced  by  using  too  small  a 
quantity  of  developer,  and  not  keeping  the  solution  in  motion 
during  development.  Crape-like  marks  occur  frequently  with 
certain  brands  of  plates,  and  seem  due  to  dirty  glass  plates. 

If,  during  drying  of  a  negative,  water  is  splashed  on  to  the 
film,  a  mark  will  occur  which  we  can  neither  account  for  nor 
efface ;  the  result  is  a  patch  lig liter  than  the  rest  of  the  nega- 
tive. 

Sometimes  a  bronze-like,  metallic-looking  scum  forms  on 
negatives  developed  with  pyro  preserved  with  sodic  sulphite. 
This  may  be  removed  with  a  rag  and  alcohol.  Whether  it  is 
identical  with  one  form  of  green  fog  we  cannot  say. 


CHAPTEE  XVII. 
PAPER  NEGATIVES  AND  STRIPPING  FILMS. 

IN  the  chemical  operations  of  developing  an  image  in  gela- 
tine emulsion,  there  is  no  difference  whether  the  film  of  gela- 
tine be  on  a  rigid,  permanent  support,  or  a  flexible,  textile, 
temporary  support,  but  of  necessity  the  manipulations  must 
be  somewhat  altered  to  suit  the  altered  circumstances.  The 
composition  of  the  solutions  for  developing,  fixing,  clearing, 
etc.,  already  given,  will  answer  for  paper  negatives  and  films 
quite  as  well  as  for  glass  plates. 

Paper  Negatives,  wherein  the  paper  remains  permanently 
the  support,  of  which,  as  a  type,  we  may  take  Eastman's  Nega- 
tive Films.  These  may  be  exposed  in  cut  sheets,  for  experi- 
ment ;  but  vastly  preferable  are  the  roll-holders  known  as  the 
Eastman-Walker.  In  one  of  these  is  placed,  with  every  con- 
venience for  exposure,  a  long  band  of  negative  paper,  to  be 
unwound  for  exposure  in  proper  quantity  and  position,  which 
can  be  determined  by  fittings  forming  essential  parts  of  the 
apparatus.  In  Fig.  20  we  show  the  latest  pattern  of  the  East- 


FIG.  20. 

man-Walker  Roll-holder,  and  as  full  instructions  are  given  in 
various  places  for  its  use,  we  need  not  waste  space  in  repeating 


THE    PROCESSES    OF    PUKE    PHOTOGRAPHY.  105 

these  instructions.  We  will,  however,  give  one  or  two  hints, 
which  we  think  may  prove  useful,  whether  "  negative  films " 
or  "  stripping  films "  are  used  in  this  roll-holder.  Although 
the  instrument  itself  registers  on  the  paper  the  extremities  of 
each  exposure,  it  is  well,  whenever  opportunity  offers — during 
a  tour,  for  instance—  to  mark  in  pencil  each  end  of  the  film  as 
it  presents  itself  when  the  shutter  is  withdrawn.  This  will 
form  a  further  safeguard,  beyond  the  small  punched  holes, 
against  cutting  up  the  film  in  the  wrong  places.  (The  neces- 
sity for  this  is  much  lessened  in  the  new  pattern.)  When 
about  to  develop  a  spool  of  exposed  films,  the  inexperienced 
will  do  well  to  cut  off  one  exposure  at  a  time,  and  develop  one 
before  he  cuts  off  another.  (The  new  pattern  is  vastly  im- 
proved in  this  respect,  also;  in  fact,  the  new  design  is  so 
superior,  in  almost  every  essential  point,  to  the  pattern  origin- 
ally introduced,  that  those  who  bought  the  original  pattern 
have  a  distinct  grievance,  that,  so  soon  after  they  had  pur- 
chased one  pattern,  another  so  greatly  superior  should  be 
brought  under  their  notice,  and  should  excite  their  covet- 
ousness  and  tempt  them  to  extravagance.) 

The  exposed  length  of  film  for  development,  being  cut  off,  is 
immersed  in  water  face  downwards  for  a  few  seconds,  being 
slidden  sideways,  if  possible,  into  the  water;  after  the  few 
seconds  have  elapsed  it  is  lifted  face  up  and  either  brushed 
over  with  a  broad  hair  brush  under  water,  or  pulled  quickly 
along  the  face  up  under  w^ater.  This  is  simply  to  prevent  air- 
bells.  Development  follows,  then  fixing,  washing,  clearing, 
washing  again.  Then  the  film  is  squeegeed  face  downwards 
to  a  polished  sheet  of  vulcanite,  where  it  is  allowed  to  dry, "and 
whence,  when  dry,  it  ought  to  strip  off  with  ease,  one  corner 
being  raised  with  a  knife  or  other  pointed  instrument. 
According  to  the  instructions,  the  negative  should  then  be 
rendered  translucent  by  the  application  of  some  oily  lubricant, 
such  as  the  "  translucine,"  sold  for  the  purpose.  Against 
this  oiling  we  protest.  Printing  truly  is  rendered  more  rapid, 
and  "grain,"  possibly,  may  be  slightly  eliminated,  but  with- 
out special  and  highly  inconvenient  means  the  negatives  so 
treated  cannot  be  preserved  for  any  considerable  length  of 


106  THE    PROCESSES   OF   PUKE   PHOTOGRAPHY. 

time.  The  best  method  by  far,  if  the  negatives  are  of  any 
nature,  is  to  leave  them  as  they  come  from  the  vulcanite. 

Stripping  films  (also  "Eastman")  are  coming  into  more 
and  more  general  use  by  rapid  strides.  In  this  case  develop- 
ment, fixing,  and  washing  are  precisely  as  before ;  but,  for 
evident  reasons,  the  paper  being  removed  finally,  the  develop- 
ment should  be  carried  a  little  further,  apparently  (i.  <?.,  as 
observed  in  the  dark-room),  than  in  the  case  of  glass  plates, 
and  considerably  further  than  in  the  case  of  paper  negative 
films.  The  Eastman  Company  strongly  advise  the  carbonate 
developer  in  place  of  the  ammonia — we  can  vouch  for  the 
excellence  of  ammonia,  and  other  authorities  can  equally 
vouch  for  the  carbonates.  The  films  should  not  be  alumed 
until  a  later  stage ;  there  is  no  necessity  for,  and  there  may  be 
danger  in,  the  alum. 

The  stripping  films,  after  fixation,  are  washed  ;  but  as  they 
have  to  undergo  several  future  washings,  the  first  need  not  be 
of  any  very  great  duration.  fA.  plate  of  glass,  a  little  larger 
than  the  film,  is  cleaned,  rubbeoT  all  over  with  powdered  talc 
(French  chalk),  the  talc  rubbed  appu.-ently  all  off,  and  the 
plate  "  edged  "  or  coated  with  a  very  thin  solution  of  pure 
India  rubber  in  benzole,  also  pure.  It  is  then  coated  with 
thin,  plain  collodion,  which,  when  set,  but  not  dry,  is  washed 
till  the  greasy  appearance  due  to  the  solvents  is  gone.  The 
film  is  now  squeegeed  to  the  collodion  film,  blotting-paper 
laid  over  the  paper  film,  and  a  weight  applied  for  at  least 
quarter  of  an  hour,  and  as  much  longer  as  convenient.  The 
paper  may  even  be  allowed  to  dry,  but  it  must  not  be  par- 
tially dry,  it  must  be  all  damp  or  all  dry.  After  a  suitable 
time  has  elapsed  the  plate  bearing  the  collodion  and  the  paper 
film  is  placed  in  water  at  about  120  deg.  Fahr.  The  tissue  is 
prepared  by  the  makers  in  this  way :  The  paper  is  coated 
with  a  fairly  thick  film  of  soluble  gelatine,  which  is  then 
calendered.  The  emulsion,  rendered  totally  insoluble  with 
alum,  follows.  So  that  when  the  tissue  is  placed  in  hot  water, 
as  above,  the  soluble  gelatine  melts  and  the  paper  can  be 
removed.  No  attempt  must  be  made  to  remove  the  paper 
until  air-bubbles  are  seen  from,  the  back  to  form  under  the 


THE  PROCESSES  OF  PUKE  PHOTOGRAPHY.         107 

paper.  The  paper  when  detached  is  thrown  away,  the  film 
washed  under  the  tap,  and  if  desired,  cleaned  in  alum  and 
acid,  and  washed  again. 

A  "skin"  (consisting  of  gelatine  and  glycerine  poured  on 
a  glass  plate,  dried  and  stripped),  is  now  soaked  for  a  few 
moments  in  water,  placed  on  the  negative  film  adhering  to  the 
glass  plate,  the  squeegee  is  gently  applied  in  sweeps  to  the 
back  of  the  skin  so  as  to  expel  air-bells  and  superfluous  water, 
and  the  whole  is  set  aside  to  dry  spontaneously.  When  the 
film  is  dry  it  is  coated  with  plain  collodion  and  again  allowed 
to  dry.  The  margins  are  then  cut  round  with  a  sharp  point, 
and  one  corner  raised  from  the  .glass,  when  the  whole  negative 
will  leave  the  glass  and  remain  in  the  hand,  a  real  thing  of 
beauty  so  far  as  its  own  inherent  qualities  are  concerned. 
The  negative  film  now  consists  of  an  image  of  silver  in  an 
extremely  attenuated  film  of  insoluble  gelatine,  strengthened 
by  the  skin,  and  the  who!e  almost  hermetically  sealed  between 
two  strata  of  damp  proof  collodion. 

It  need  not  be  matter  for  surprise  if  the  beginner  find  some 
little  trouble  in  such  a  series  of  operations,  but  a  little  practice 
and  thought  will  enable  anyone  to  make  a  certain  success  of 
the  stripping  operations.  The  accidents  most  frequent  are : 

"  Grain"  appearing  in  certain  parts  of  the  negative.  Due 
to  the  soluble  gelatine  substratum  being  too  thin.  Remedy : 
Reject  or  return  at  once  to  the  maker  all  the  spools  bearing 
that  batch  number.  This  fault  has  been,  by  the  perseverance 
and  care  of  the  makers,  almost  or  entirely  eliminated  from  all 
the  stripping  films  we  have  seen  of  late. 

The  paper  refuses  to  strip  from  the  film  on  glass.  Sub- 
stratum becomes  insoluble  from  tanning  in  prolonged  pyro 
development,  or,  more  probably,  the  film  has  been  kept  too 
long  before  use. 

The  whole  film  threatens  to  leave  the  glass  in  the  hot  water. 
Dirty  plate,  improperly  talced,  collodion  not  properly  washed, 
stripping  too  soon  after  squeegeeing,  castor  oil  or  greasy 
matter  in  the  collodion,  India  rubber  solution  too  thick. 

Blisters  after  stripping.  Water  too  hot,  acid  in  "  clearing 
solution"  too  strong,  collodion  oily,  plate  dirty,  talcing  im- 


108  THE    PROCESSES    OF    PUKE   PHOTOGRAPHY. 

After  the  "  skin "  is  applied  and  when  film  is  nearly  dry, 
film  showing  tendency  to  jump  from  the  plate.  Skin  not 
enough  soaked.  In  certain  cases,  especially  in  hot  weather,  a 
little  glycerine  may  be  added  to  the  water  in  which  the  skin  is 
soaked.  The  thinner  the  skin  and  the  warmer  the  water  the 
less  soaking  is  required;  in  extreme  cases  the  skin  may  be 
simply  passed  through  the  water.  A  thick  skin  must  be 
soaked  till  just  limp.  If  the  glass  plate  be  not  coated  or  edged 
with  rubber,  or  if  the  collodion  be.  too  thick,  the  film  may 
spring  from  the  plate  prematurely. 

The  film,  when  dry,  refuses  to  strip  from  the  plate,  a  very 
unlikely  cause  of  failure.  Dirty  plate,  want  of  talc,  or  too 
much  left  on  plate,  or  the  plate  too  much  polished  after 
talcing. 

The  finally  stripped  film,  if  not  quite  flat,  may  be  placed 
under  pressure  after  the  face  has  been  rubbed  with  the  soft 
part  of  the  hand  to  remove  the  thin  fiim  of  rubber  due  to  the 
coating  of  the  plate  with  rubber  solution,  if  the  plate  was  so 
coated. 

There  is  no  necessity  for  stripping  a  film,  unless  we  choose, 
before  a  trial  print  is  taken  from  it.  It  can  be  dried  after  fix- 
ing and  washing,  but  not  alumed,  and  can  be  stripped  at  any 
future  time.  But  in  this  case  the  film  must  be  well  soaked  in 
water  before  squeegeeing  to  glass  plate,  and  the  water  for 
stripping  will  probably  require  to  be  hotter.  As  a  rule,  hot 
water  entails  no  danger  to  the  emulsion,  we  have  stripped  in 
boiling  water,  but  this  ought  not  to  be  needed,  and  certainly  is 
not  recommended. 

In  cases  where  reversal  of  right  and  left  is  a  matter  of  no 
consequence,  as  in  portraiture  in  certain  cases,  the  final  strip- 
ping need  not  be  resorted  to.  The  film,  minus  the  paper,  can 
be  left  adhering  to  the  glass  plate  in  a  reversed  position,  in 
fact,  for  certain  purposes  this  is  a  necessity,  while  for  other 
purposes  it  is  immaterial  one  way  or  the  other. 

There  are  other  tissues  and  films  on  the  market,  some  of 
which  give  promise  of  future  excellence,  if,  indeed,  they  do  not 
already  possess  merit.  So  far  as  we  have  seen  the  failing  in 
these  transparent  films  has  been  not  in  the  support  so  much  as 


THE  PROCESSES  OF  PUKE  PHOTOGRAPHY.         109 

in  the  emulsion  itself,  which  has,  in  our  experience,  often  been 
of  inferior  quality,  and  carelessly  applied.  A  London  firm,  is' 
now  coming  into  notice  with  a  film  which  we  ourselves  intro- 
duced to  the  notice  of  the  firm,  the  Yergara  Film  Co.  The 
film  in  this  case  consists  of  gelatine  heavily  chromated,  and  is 
certainly  beautifully  transparent ;  of  the  general  qualities  of 
the  tissue  we  have,  at  the  time  of  writing,  had  little  oppor- 
tunity of  judging. 


CHAPTEK  XYIII. ' 

"COLOR-CORRECT,"  OR  "ORTHOCHROMATIC  " 
PHOTOGRAPHY. 

EVERY  one  who  has  had  even  slight  experience  of  photog- 
raphy must  have  noticed  the  fact,  that  the  color  yellow,  which 
appears  brightest  of  all  the  colors  to  the  eye,  is  rendered  on  a 
photographic  negative  as  nearly  clear  glass,  and  on  a  print  as 
nearly  black,  while  the  dark  blues  of  nature,  so  little  brilliant 
to  the  eye,  are  rendered  as  more  or  less  high-lights,  dark  on  the 
negative,  and  light  on  a  positive.  Clearly  this  is  a  defect  of, 
and  a  reproach  to,  photography,  and  any  means  by  which  we 
may  more  correctly  render  the  visual  value  of  these  colors  must 
be  welcomed.  Great  steps  have  been  made  of  late  years  in 
this  respect,  and  greater  would  doubtless  have  been  made  had 
not  researches  into  the  matter  been  more  or  less  hampered  by 
patents  in  certain  countries. 

It  is  very  long  since  the  d'scovery  was  made  that  by  photo- 
graphing certain  colored  obj_cts  through  yellow  media  the 
color  values  were  more  correctly  rendered,  a  certain  amount  of 
the  actinic  blue  and  violet  being  shut  out  by  the  yellow 
medium. 

This  was,  indeed,  a  short  step  in  the  right  direction ;  of  late 
much  greater  strides  have  been  made,  for  gelatine-bromide  films 
have  been  produced,  actually  more  sensitive  to  the  yellow  and 
yellow-green  of  the  spectrum,  than  to  the  blue  and  violet.  As  a 
rule  films  are,  by  treatment  with  certain  aniline  dyes,  made  much 
more  sensitive  to  the  yellow,  yellow-green,  and  even  to  the  red 
rays  than  they  are  normally  without  such  treatment ;  and  the 
action  is  farther  eked  out  by  the  use  of  yellow  screens,  which 
further  decrease  the  disproportion  ate  actinism  of  the  blues  and 
violets  by  partly  "  filtering  out  "  these  portions  of  the  normal 
spectrum. 


THE    PROCESSES    OF    PUKE    PHOTOGRAPHY.  Ill 

It  must  be  clearly  understood  that  the  action  of  the  dyes  is 
not  merely  a  staining  action  ;  the  staining  has  undoubtedly  an 
effect,  per  se,  but  the  important  factor  in  the  matter  is  the 
new  compound  formed  by  the  combination  of  the  dye  with 
the  silver  in  the  film,  or  in  the  emulsion.  Nor  must  it  be 
forgotten  that  outside  the  solar  spectrum  there  is  no  existing 
pure  blue  or  any  other  color,  and  we  have,  moreover,  always 
to  take  into  account  reflection.  The  yellow  color  of  an  object 
may  be  due  to  a  mixture  of  colors  by  no  means  identical 
with  prismatic  yellow ;  ar\d  the  light  reflected  from  an  object 
may  completely  upset  all  our  impressions  as  to  the  real  color 
of  that  object.  This  reflected  white  light  renders  our  plates 
(however  we  may  have  endowed  them  with  "  color-sensitive- 
ness ")  relatively  less  orthochromatic  by  increasing  the  inten- 
sity of  the  blues  and  violets. 

The  substances  most  commonly  used  for  gelatine  plates  are 
cosine  compounds,  such  as  the  dyes  known  as  erythrosine, 
rose  bengal,  and  cosine  itself,  and  with  these  is  generally 
used  an  alkali,  viz.,  ammonia.  The  form  in  which  these  are 
used  is  generally  that  of  a  bath  applied  to  the  coated  and 
dried  plate,  but  frequently  the  dye  is  added  to  the  emulsion 
in  bulk  in  the  liquid  state  before  plates  are  coated.  We  shall 
confine  our  attention  to  the  process  of  bathing  a  ready-pre- 
pared plate.  Every  precaution  must  be  taken  to  guard  against 
fog  as  the  plates  are  rendered  not  only  highly  sensitive  to 
yellow  and  orange,  but  also  strongly  alkaline  in  reaction,  in. 
which  state  a  plate  is  always  highly  susceptible  to  fog,  not 
only  from  light,  but  from  every  sort  of  noxious  vapor.  The 
light  used  must  be  of  the  deepest  ruby  color,  and,  indeed,  the 
less  of  even  that  used  the  better.  Certain  dyes  also  fog  plates 
even  in  darkness. 

A  plate  should  be  chosen  with  an  emulsion  containing  little 
or  no  silver  iodide;  we  have  known  as  little  as  three  parts  of 
iodide  per  centum  of  bromide  to  nullify  our  attempts  to  get  a 
good  orthochromatic  effect.  The  plate  is  first  bathed  for  two 
minutes  in  a  solution — 

Liquor  ammonia 1  part 

Water...  100  parts 


112         THE  PROCESSES  OF  PUKE  PHOTOGRAPHY. 

Then  without  washing  immerse  in 

Dye  (eosine  "  B,"  erythrosine  or  rose  bengal,  etc.)          1  part 

Water 10,000  parts 

Ammonia 100  parts 

The  most  convenient  way  to  arrive  at  these  very  dilute 
solutions  of  the  dye  is  as  follows.  Make  first  an  aqueous 
solution  of  (say) 

Erythrosine 1  part  (1  gram,  for  instance) 

Water 1000  parts  (1000  c.c.  for  instance) 

This  may  be  kept  a  considerable  time  in  the  dark. 

The  ordinary  10  per  cent,  ammonia  solution  may  be  used. 

Then  take 

Dye  (1  to  1000) 1  part 

Ammonia  (10  per  cent.) 1  part 

Water 8  parts 

Some  dyes  useful  for  this  purpose  are  insoluble  in  water ; 
in  these  cases  alcohol  (absolute)  may  be  used  for  the  first 
solution :, 

Dye  (as  cyanine). 1  part  (1  gram,  for  instance) 

Absolute  alcohol 1,000  parts  (1000 c.c.,  for  instance) 

Some  workers  find  difficulty  in  using  the  alcoholic  solutions, 
as  there  is  a  marked  tendency  to  uneven  staining  of  the  plates. 

Mr.  J.  B.  Wellington,  of  London,  has  shown  a  way  to  over- 
come the  awkward  precipitation  that  takes  place  when  cyanine 
is  dissolved  in  water. 

Prof.  C.  H.  Bothamley,  F.I.C.,  F.C.S.,  of  Leeds,  has  done 
much  to  elucidate  the  practice  and  principles  of  this  process, 
his  writings  may  be  found  in  files  of  the  Photographic  JVews, 
1887,  and  elsewhere.  We  mention  his  name  simply  because 
it  has  been  prominently  brought  forward  lately,  and  not  at 
all  to  the  exclusion  of  others,  as  Yogel,  Eder,  Ives,  Abney, 
Schumann,  &c. 

We  have  said  that  in  many  cases,  in  order  to  get  the  best 
effect,  we  require  to  use  a  yellow  "  screen."  This  may  be  of 
yellow  glass,  but  the  sides  of  the  glass  must  be  absolutely 


THE  PROCESSES  OF  PURE  PHOTOGRAPHY.         113 

parallel.  A  much,  better  plan  is  to  dissolve  aurantia  dye  in 
alcohol  and  to  mix  the  alcohol  with  plain  collodion,  which  is 
poured  upon  a  talced  glass  plate,  and  when  dry  stripped.  A 
piece  of  this  collodion  film  may  be  fixed  by  any  suitable  per- 
manent or  temporary  means  over  the  aperture  of  the  lens 
diaphragm.  But  the  screen  must  be  used  with  discretion. 
The  same  screen  will  not  answer  for  all  purposes.  The  more 
intense  the  blues  with  which  we  have  to  deal,  the  darker 
should  be  the  yellow  stain.  With  artificial  light,  as  gas  or 
paraffin,  the  screen  will  probably  not  be  required  at  all.  In 
such  a  light  the  general  sensitiveness  of  the  dyed  plate  will  be 
found  very  great. 

For  landscape  work,  on  account  of  the  reflections  already 
mentioned,  a  very  dark-yellow  screen  is  usually  required,  but, 
again,  it  is  pointed  out  that  in  the  yellow  or  reddish  light  of 
approaching  sunset  a  screen  is  not  needed  at  all.* 

It  is  within  the  mark  to  say  that  in  color-correct  photog- 
raphy lies  the  future  of  the  science  and  of  the  art. 

At  the  conference  of  the  Camera  Club,  in  March,  1888, 
Captain  Abney  read  a  paper  relating  to  his  theories  on  ortho- 
chromatic  processes.  He  recommended  the  application  to  the 
dried  gelatine  film  of  collodion  or  varnish  containing  certain 
suitable  dyes,  but  we  are  not  aware  of  success  having  followed 
this  practice  in  any  hands,  other  than  those  of  the  Captain, 
who,  indeed,  probably  used  the  process  for  his  own  special 
purposes  of  spectrum  photography. 

Of  all  the  processes  tried  by  the  writers,  none  seems  to  them 
more  satisfactory ;  certainly  none  is  more  simple  than  that 
last  suggested  by  Mr.  Ives,  of  Philadelphia.  It  may  be  stated 
thus : 

In  four  ounces  of  absolute  alcohol  dissolve  one  grain  of 
erythrosine  or  cyanine.  Soak  the  gelatine  bromide  plate  in 
this  for  a  minute.  Allow  to  dry.  Wash  for  a  short  time  in 
running  water.  Dry,  and  use.  Xo  alkali  is  used.  The  plates 

*  There  is  a  danger  in  using  a  screen  too  dark -yellow  for  landscape  ; 
in  such  a  case  the  foliage  may  be  represented  in  the  print  as  light  where 

tV»#*  ortict-  inf-£»nrl^rl    it  fr»r  th#»  cVinrlnTO-  rtf  Vi  i  c  r\irtiirp 


114 


THE   PROCESSES   OF   PURE   PHOTOGRAPHY. 


keep  well.  The  cyanine  renders  the  plates  so  very  sensitive, 
even  to  red  rays,  that  these  operations,  as  well  as  development, 
must  be  conducted  practically  in  darkness.  The  erythrosine 
formula  has  proved  in  our  hands  eminently  satisfactory,  the 
cyanine  no  less  so,  but  the  precautions  necessary  with  it  apt  to 
be  irksome. 


CHAPTER  XIX. 
STEREOSCOPIC  PHOTOGRAPHY. 

As  WE  see  a  natural  object  with  two  eyes  at  once,  and  as 
our  eyes  are  about  two  and  a-half  inches  apart,  it  is  plain 
that  we  really  see  two  images  from  slightly  different  bases,  or 
points  of  view ;  our  right  eye  sees  rather  more  of  the  right  side 
of  the  object  than  our  left  eye  sees,  and  vice  versa.  Yet  our 
vision  and  our  brain  so  work  together  that  we  do  not,  as  a  rule, 
see  objects  double,  but  single.  Photography,  in  producing 
stereoscopic  pictures,  imitates  nature  in  her  provisions  for 
enabling  us  to  see  things  with  a  certain  amount  of  roundness 
or  solidity,  and  for  enabling  us,  to  a  certain  extent,  to  realize 
the  distances  between  objects  on  different  planes. 

At  one  time  stereoscopic  photography  was  a  fashion,  if  not 
a  craze ;  and  when  the  fashion  died  out,  so  great  was  the  reac- 
tion that  from  a  position  of  undue  importance,  stereoscopic 
photography  fell  into  a  position  of  unmerited  contempt.  In 
England,  of  late,  it  has  been  once  more  attracting  attention, 
and  we  think  we  shall  not  do  amiss  by  saying  a  few  words  on 
the  subject. 

The  camera  used  for  this  class  of  work  is  provided  either 
with  one  lens  fitted  to  a  long-range  sliding  front,  so  that  after 
one  picture  is  taken  the  lens  is  slid  about  two  and  a-half  to 
three  inches  to  one  side,  and  another  picture  is  taken  ;  or  the 
camera  has  two  lenses,  side  by  side,  their  centres  distant  about 
two  and  a-half  to  three  inches,  and  their  foci  exactly  equal,  for 
which  reason  they  are  often  called  "  twin "  lenses.  Three 
inches  is  by  no  means  the  limit  of  separation,  for  with  a  dis- 
tance of  only  three  inches  between  the  axis  of  the  lenses,  ob- 
jects at  a  distance  will  not  be  shown  stereoscopically  at  all ;  we 
have  ourselves  moved  the  whole  camera  several  feet,  with  cer- 


116  THE    PROCESSES   OF   PUKE   PHOTOGRAPH Y. 

tain  precautions,  and  succeeding  in  producing  stereoscopic 
effect,  where,  without  that  proceeding,  we  should  have  got 
none.  But  for  near  objects,  three  inches  will  be  found  quite 
sufficient. 

If  the  camera  be  moved  at  all,  it  must  be  moved  only  hori- 
zontally on  the  axis  of  the  lens ;  or,  in  other  words,  both 
views  must  be  taken  on  the  same  base-line.  Various  ingenious 
devices  for  shifting  the  camera  in  this  manner  on  its  stand 
have  been  designed. 

The  usual  size  of  a  "  stereo  "  plate  is  6f  x  3^  inches,  but,  so 
long  as  the  centres  of  the  mounted  prints  are  not  over  2-f  or  3 
inches  apart,  the  height  need  not  be  limited  to  3  J  inches ;  in 
fact,  we  have  seen  very  fine  stereographs  five  inches  high, 
Mr.  J.  Traill  Taylor,  whose  authority  on  such  subjects  can- 
not be  impugned,  recommends  for  stereo-work  a  plate  8x5 
inches. 

A  little  consideration  will  show  that  if  .the  two  halves  of  the 
stereoscopic  picture  are  taken  on  one  plate,  these  halves  will 
require  to  be  transposed  if  the  view  is  to  be  seen  stereoscopic- 
ally,  unless  they  are  purposely  transposed  on  the  plate  by  tak- 
ing the  right  view  on  the  left  side  of  the  plate  and  the  left 
view  on  the  right.  A  camera  and  slide  used  to  be  made  for 
this  very  purpose  of  transposing,  but,  as  a  rule,  cameras  now 
made  for  stereo-work  are  "  binocular,"  i.  e.,  consist  practically 
of  two  cameras,  side  by  side,  a  division  stretching  inside  the 
full  size  camera  from  front  to  rear.  In  cases  where  a  binocu- 
lar camera  is  used,  the  two  prints  must  always  be  transposed 
in  mounting,  unless  the  two  negatives  are  transposed  in  print- 
ing. The  negatives  to  be  transposed  may  be  cut  down  the 
centre  with  a  diamond,  if  glass,  or  with  a  pair  of  scissors,  if 
paper,  and  may  then  be  printed  side  by  side  in  the  transposed 
position ;  but,  unless  the  negatives  are  trimmed  according  to 
the  following  rules,  there  is  no  gain  in  dividing  the  two 
halves. 

Some  persons  can  see  stereographs  without  a  stereoscope, 
but  probably  these  persons  are  few.  Certainly  most  persons 
require  a  stereoscope  for  the  purpose.  "With  a  "reflecting 
stereoscope,"  pictures  of  almost  any  size  can  be  seen,  but  the 


THE    PROCESSES    OF    PUKE    PHOTOGRAPHY.  1  1  7 

instrument  commonly  used  is  the  well-known  "  refracting 
stereoscope."  We  cannot  enlarge  on  this  instrument  further 
than  to  say  that  the  majority  of  those  in  the  market  are  use- 
less. The  lenses  should  be  adjustable  as  to  their  distance  from 
each  other,  to  suit  various  pairs  of  eyes.  . 

The  crucial  point  in  stereography  is  mounting  the  prints. 
We  shall  suppose  that  the  negatives  have  not  been  transposed, 
and  that  we  have  to  mount  a  double  print,  the  sides  having  to 
be  transposed. 

First,  we  have  to  determine  a  J)ase  line.  The  first  trimming- 
line  is  to  be  drawn  so  that  it  cuts  a  given  object  in  the  fore- 
ground of  each  half  at  precisely  the  same  point.  The  top  of 
the  prints  is  then  to  be  trimmed  parallel  with  the  base  line. 
Next,  the  two  halves  have  to  be  separated  and  transposed. 
The  pictures  are  to  be  mounted  so  that  their  centres  shall  be 
not  less  than  two  and  three-quarter  inches  nor  more  than  three 
inches  apart.  In  trimming  the  sides  of  the  pictures,  we  must,  m 
on  the  print  that  is  to  be  mounted  on  the  right-hand  side, 
leave  more  subject  on  the  right  than  we  leave  on  the  right  of 
the  left-hand  picture ;  and  on  the  left-hand  picture  we  must 
leave  more  of  the  left  side  than  we  leave  on  the  left  of  the 
right-hand  picture.  In  other  words,  we  must  trim  the  right 
picture  a  little  more  to  the  right  of  any  given  object 
appearing  in  both  halves,  and  we  must  trim  the  left-hand 
picture  a  little  further  to  the  left  than  we  trim  the  right-hand 
picture,  and  still  we  must  keep  the  pictures  exactly  the  same 
size,  and  their  centres  the  distance  apart  already  specified 
(read  "British  Journal  Almanac,  1887,"  article  of  the  editor.) 


CHAPTER  XX. 

PART  II. 
PRINTING  PROCESS— PRELIMINARY. 

WE  have  so  far  treated  almost  entirely  of  processes  for  pro- 
ducing negatives,  we  now  come  to  processes  for  producing 
positives,  or  prints. 

Printing  may  be  by  "  contact "  or  by  "  enlargement,"  or 
by  "reduction";  the  image  may  be  "printed  out"  or  "devel- 
oped," on  paper,  glass,  opal,  cloth,  etc.  Lastly,  a  print  may 
be  on  an  opaque  support  or  on  a  translucent  support  used  as 
opaque ;  or  it  may  be  on  a  transparent  support,  as  glass 
("  transparent  positive,"  or  "  transparency,"  or  "  lantern- 
slide,")  or  it  may  be  on  a  translucent  support,  as  an  "  opal 
transparency." 

The  order  which  we  propose  to  follow  is,  first,  printing  on 
paper  with  silver  salts ;  second,  printing  on  paper  with  salts 
not  of  silver ;  third,  the  processes  specially  adapted  for  pro- 
ducing the  beautiful  and  useful  positive  known  as  a  lantern- 
slide. 

The  Printing  Frame. — We  may  once  for  all  dispose  of 
the  mechanical  operations  of  printing  by  contact,  they  are  of 
the  simplest  description.  The  only  apparatus  actually  neces- 
sary is  a  "  printing  frame,"  which  is  merely  an  arrangement 
for  holding  the  negative  and  the  sensitive  surface  firmly 
together  face  to  face,  and  for  allowing  the  progress  of 
printing  to  be  observed  without  danger  of  moving  the  two 
from  the  position  with  relation  to  each  other  in  which  they 
were  originally  placed.  Two  kinds  of  printing  frames  are 
Figs.  21  and  22,  each  typical  of  a  class.  Fig.  21  shows  the 


THE  PROCESSES  OF  PUKE  PHOTOGRAPHY.         119 

appearance  of  the  lighter  class  of  printing  frame,  and   this 
style  is  usually  made  to  take  in  its  rebate  one  size  of  negative 


FIG.  21. 

only,  while  Fig.  22  is  heavier,  being  furnished  with  a  plate  of 
glass  which  ought  to  be  "  plate  glass,"  or  at  least  perfectly 


FIG. 


flat  to  avoid  breakage  of  negatives.  The  springs  in  this  latter 
frame  should  be  strong  so  as  to  insure  perfect  contact  at  all 
times  between  negative  and  sensitive  surface. 


120  THE    PROCESSES^  OF   PURE   PHOTOGRAPHY. 

The  negative  is  laid  face  up  in  one  of  these  frames,  the 
sensitive  material  is  laid  face  down  on  top  of  the  negative, 
a  pad,  or  several  pads,  of  paper,  felt,  or  cloth  is  placed  next 
the  sensitive  material,  the  back  of  the  frame  covers  the  pad, 
and  the  frame  is  closed.  It  is  then  placed  with  its  front  to 
the  light.  The  printing-room  should  be  dry  but  cool. 

The  back  of  the  frame  is  hinged  so  that  one-half  can  be 
turned  back  and  the  progress  of  printing  examined  without 
shifting  the  position  of  the  other  half. 

In  large  sizes  two  hinges  are  to  be  recommended.  Indeed, 
an  8x10  double-hinged  printing-frame  has  often  made  its  con- 
venience felt  to  the  writers. 

For  printing  processes  where  "  combination  "  printing  may 
be  required,  special  "  registering "  frames  are  made ;  we  do 
not  think  it  necessary  to  describe  these. 


CHAPTER  XXI. 

PRINTING  ON  ALBUMENIZED  PAPER  WITH  SILVER 
CHLORIDE. 

IN  this  process,  paper  of  specially  good  quality  is,  by  means 
of  special  appliances,  coated  with  albumen  (or  white  of  egg), 
containing  a  certain  proportion  of  a  soluble  chloride,  usually 
ammonium  chloride.  When  this  is  floated  on  a  solution  of 
silver  nitrate  of  sufficient  strength,  silver  chloride  is  formed 
by  double  decomposition  and  the  silver  chloride  remains  in  the 
albumen  in  conjunction  with  a  certain  excess  of  silver  nitrate, 
a  necessary  condition  for  success.  The  silver  chloride  black- 
ens on  being  exposed  to  light,  but  there  is  a  further  combina- 
tion which  exercises  an  important  influence  on  our  results  and 
on  our  operations :  that  combination  being  one  between  the 
silver  nitrate  and  the  albumen,  and,  further,  probably  between 
the  silver  nitrate  and  the  "size"  of  the  paper.  The  presence 
of  these  organic  silver  salts  accounts  for  much  of  the  beauty 
and  many  of  the  disadvantages  of  this  process. 

It  would  be  hopeless  for  anyone  not  in  the  trade  to  attempt 
to  produce  salted  albumenized  paper  of  quality  comparable  to 
that  made  by  the  few  firms  who  produce  albumenized  paper ; 
we,  therefore,  shall  accept  as  certain  that  our  reader  will  pur- 
chase for  his  work  paper  ready-albumenized  and  salted.  On 
the  quantity  of  soluble  chloride  in  the  albumen  depends  chiefly 
the  strength  of  the  "sensitizing"  bath,  and,  as  a  rule,  instruc- 
tions accompany  each  sample  of  paper  sold. 

Sometimes  the  paper  presents  a  very  high  gloss,  and  is 
called  "  double  albumenized ;"  this  paper  is  slightly  more 
difficult  to  work,  but  the  results  are  by  many  considered 
superior. 

The  sensitizing  bath  consists  of  a  neutral  solution  of  silver 


122  THE   PEOCESSE8   OF   PURE   PHOTOGRAPHY. 

nitrate,  varying  from  about  forty  to  sixty-five  grains  of  silver 
nitrate  to  each  ounce  of  water.  A  bath  of  lower  grade  than 
thirty  grains  to  the  ounce  will  fail  to  effect  the  necessary 
coagulation  of  the  albumen,  but  in  the  other  direction  we  may 
go  far  beyond  a  sixty-five-grain  bath.  A  large  quantity  of 
chloride  in  the  albumen  and  a  double  albumen i zed  paper  indi- 
cate a  strong  bath,  as  a  rule,  but  the  condition  of  the  albumen 
must  also  regulate  the  strength  of  the  bath. 

The  time  of  notation  necessary  also  requires  consideration. 
The  albumenized  salted  paper  is  floated  on  the  solution  of  sil- 
ver nitrate ;  if  we  do  not  float  long  enough  we  get  poor  prints, 
if  we  float  too  long  we  waste  silver.  "We have  to  utilize  all  the 
salt  in  the  paper,  and  in  order  to  make  certain  that  all  the  solu- 
ble chloride  is  converted  into  silver  chloride,  we  use  the  follow- 
ing pretty  and  simple  test.  A  solution  of  potassic  chromate 
five  grams,  water  one  ounce,  is  made,  and  a  drop  put  on  the 
back  of  the  paper  to  be  timed.  The  paper  is  now  floated 
(albumen  downwards)  on  the  silver  bath,  the  time  being  care- 
fully noted ;  when  the  originally  yellow  spot  of  chromate  has 
become  deep  orange  color,  the  conversion  is  complete ;  this 
will  form  a  guide  to  the  time  required  when  the  serious  opera- 
tion of  sensitizing  larger  sheets  is  in  progress. 
"We  may  take  as  a  normal  sensitizing  bath  : 

Silver  nitrate 60  grains 

Distilled  water 1  ounce 

Tested  with  litmus,  and  if  acid,  neutralized  with  sodic  car- 
bonate. The  worker  must  determine  for  himself  the  size  of 
sheet  he  is  to  sensitize  at  one  time,  and  a  white  porcelain  dish, 
scrupulously  clean,  will  be  found  the  most  convenient  receptacle 
for  the  solution. 

As  sheet  after  sheet  of  paper  is  sensitized,  the  strength 
of  the  bath  naturally  falls,  as  of  course  a  certain  quantity  of 
the  silver  nitrate  is  converted  by  the  chloride  in  each  sheet,  and 
further,  the  bulk  is  also  diminished.  The  latter  is  of  less  mo- 
ment than  the  former  matter ;  both  may  be  met  by  making  up 
the  deficiency  in  bulk,  with  a  more  concentrated  solution  than 
that  constituting  the  bath.  Our  reserve  stock  solution  may  be 
about  100  grains  of  silver  nitrate  to  each  ounce  of  water,  and 


THE    PROCESSES    OF    PURE    PHOTOGRAPHY.  123 

the  addition  of  this  in  sufficient  quantity  to  keep  our  bath  up 
to  its  original  bulk  will  probably  suffice  to  keep  it  up  also  to 
its  original  strength.  The  "  argentometer  "  will  not  here  give 
us  correct  readings,  on  account  of  the  organic  salts,  sure  to  be 
present  in  the  bath  solution  ;  and  we  may,  to  make  sure  that 
our  solution  is  up  to  a  certain  standard,  use  the  following  in- 
structive test. 

We  first  determine  what  is  the  minimum  grade  to  which ' 
our  bath  may  be  allowed  to  fall,  the  test  will  inform  us 
whether  or  not  the  bath  has  fallen  below  that  minimum. 

We  require  the  chromate  solution  already  formulated  on 
another  page.  We  further  require  a  solution  of  potassic  bro- 
mide of  one  or  other  of  the  following  standard  strengths.  In 
making  up  the  bromide  solution  we  must  weigh  out  the  solid 
bromide,  dissolve  it  in  less  than  an  ounce,  and  then  make  up 
to  an  ounce  of  water. 

For  a  minimum  grade  of  silver     We  make  a  solution  of 
nitrate  per  ounce  of  bath.  potassic  bromide. 

50  grains  35     grains  ]  To  £ach 

55  grains  38.5  grains  j  Qunce  Q{ 

60  grains  42     grains  V  bromide 

65  grains  45.5  grains  I  soludon 

70  grains  49     grains  J 

We  Jill  a  small  pipette  with  the  best  bromide  solution,  and 
put  the  contents  of  the  pipette  into  a  white  cup  or  saucer,  and 
add  to  it  about  20  times  its  measure  of  water.  We  then  put 
in  enough  of  the  chromate  solution  to  make  this  faintly  yellow. 
Having  cleaned  out  the  pipette,  we  fill  it  with  the  bath  solu- 
tion under  test,  and  we  let  the  bath  solution  fall,  drop  by  drop, 
into  the  faintly  yellow  bromide  solution.  As  each  drop 
touches  the  solution  at  first,  a  red  stain  will  appear,  but  will 
immediately  disappear  on  stirring,  but  as  the  dropping  goes  on 
a  point  will  finally  be  reached  when  the  red  stain  will  become 
permanent,  and  will  not  disappear  on  any  amount  of  stirring. 
If  this  critical  point  be  reached  just  as  our  pipette  is 
empty,  the  bath  is  just  about  our  minimum  standard; 
if  the  red  become  permanent  before  our  pipette  is  empty, 
the  bath  is  above  our  standard;  but  if  we  have  to  add 


124  THE    PBOCESSES    OF   PUEE    PHOTOGRAPHY. 

a  few  drops  of  the  bath  after  the  pipette  is  empty  to  make 
.the  red  disappear,  then  our  bath  is  below  our  standard; 
and  with  a  little  practice,  by  noting  how  much  extra  bath  solu- 
tion is  required,  we  shall  be  able  to  judge  approximately  how 
much  our  bath  is  below  "  par." 

After  a  few  sheets  of  paper  have  been  sensitized,  the  bath 
solution  will  become  discolored,  owing  to  the  presence  of 
organic  salts.  In  this  case  add  to  the  solution  a  few  drops  of 
a  concentrated  solution  of  sodic  carbonate  till  the  bath  is 
neutral,  shake  up,  and  place  in  strong  day — or  sun — light. 
A  black  precipitate  will  fall  to  the  bottom  ;  this  is  to  be 
filtered  out.  Thereafter,  add  a  little  more  soda  to  the  bath 
and  it  is  ready  for  use  again. 

Manipulations  of  Sensitizing. — Keep  the  albumenized 
paper  in  a  place  slightly  damp,  as  a  cellar,  for  some  hours  at 
least  previous  to  sensitizing.  The  sensitizing  solution  is 
poured  into  a  flat  porcelain  or  glass  dish,  the  depth  of  solution 
being  not  less  than  half  an  inch.  Bend  the  sheet  to  be 
sensitized  into  a  loose  roll,  albumen  inward,  for  a  moment 
or  two ;  seize  two  opposite  corners  of  the  sheet  with  the  two 
first  fingers  and  thumb  of  each  hand,  knuckles  upward ; 
make  the  middle  of  the  sheet  droop,  albumen  downward,  so 
as  to  meet  the  surface  of  the  solution  evenly ;  lower  the  ends 
of  the  sheet  gradually,  but  without  stoppage,  till  the  whole 
sheet  lies  flat  on  the  solution.  Or  one  end  of  the  paper  may 
first  be  brought  into  contact  with  the  solution,  and  the  rest  of 
the  sheet  slidden  onto  the  solution.  For  instance,  if  the  left 
side  of  the  sheet  is  to  touch  the  solution  first,  lower  it  to  the 
right-hand  side  of  the  dish,  and  slide  it  gradually  to  the  left, 
lowering  the  other  parts  of  the  sheet  all  the  time.  If  in  either 
case  the  ends  seem  inclined  to  rise  up,  blow  them  down  with 
the  breath  or  touch  them  gently  with  a  clean  instrument. 
No  bath  solution  should  get  on  the  back  of  the  paper.  And 
in  either  case,  after  the  sheet  lies  flat,  each  corner  should 
be  raised  in  turn  and  air-bells,  if  found,  burst  with  a  sharp 
point,  as  of  a  quill  or  silver  instrument.  We  have  already 
given  directions  for  regulating  the  time  of  flotation ;  it  will 
be  found  to  vary  from  three  to  five  minutes,  depending  to  a 


THE    PROCESSES    OF    PUKE    PHOTOGRAPHY.  125 

considerable  extent  upon  temperature.  Flotation  and  drying 
should  be  carried  on  by  yellow  light ;  naked  gas,  or  lamp  light 
is  quite  safe. 

When  the  notation  is  complete  the  paper  is  to  be  taken  by 
one  end  or  corner  with  horn  forceps  or  a  silver  instrument, 
and  being  seized  in  finger  and  thumb  of  each  hand  is  to  be 
very  slowly  removed  from  the  bath.  It  may  be  drawn  over 
the  edge  of  the  dish,  or  over  a  glass  rod  for  the  purpose  fixed 
over  the  dish  in  some  suitable  manner.  The  paper  is  then 
hung  up  to  dry  in  a  well- ventilated  room.  It  may  be  hung 
by  two  corners  by  glass  clips,  or  it  may  be  laid  over  glass 
rods  face  upward.  The  only  danger  is  that  the  corners 
drying  first  may  curl  inward  and  damage  the  wet  or  damp 
centre.  There  will  probably  be  no  trouble  in  this  drying 
matter.  A  small  piece  of  bibulous  paper  should  be  pressed 
against  any  corner  that  shows  signs  of  collecting  a  drop,  and 
these  bits  of  paper,  as  well  as  all  filter  papers  used  for  silver 
nitrate  solutions,  should  be  laid  aside  for  future  reduction 
with  other  residues  (see  chapter  on  residues,  page  182.)  When 
the  paper  is  surface  dry,  and  before  it  has  curled  seriously,  it 
may  with  advantage  be  laid  out  flat  between  sheets  of  pure 
blotting  paper  and  so  preserved  under  weight. 

Paper  prepared  in  this  way  will  turn  yellow  in  periods 
ranging  from  twenty -four  to  forty-eight  hours,  unless  specially 
treated  in  one  of  the  ways  to  be  described  presently. 

Fuming  sensitized  paper  is  a  very  common  practice  in 
America,  and  it  presents,  under  certain  circumstances,  indu- 
bitable advantages.  The  process  of  fuming  consists  simply 
in  shutting  up  the  sensitized  paper  in  a  cupboard  with  a 
saucer  of  liquor  ammonia.  The  paper  is  hung  by  clips  to  the 
upper  part  of  the  press  and  the  ammonia  is  placed  in  the 
lower  part.  This  system  is  particularly  beneficial  when  the 
paper  is  apt  to  get  too  dry.  Paper  fumed  in  this  way  is  prob- 
ably even  more  liable  to  the  yellowing  described  in  last  para- 
graph. 

To  preserve  sensitized  albumen  paper — that  is  to  say,  to 
prevent  the  yellow  discoloration  just  mentioned,  soak  stout 
blotting-paper  in  a  half -saturated  solution  of  sodic  carbonate, 


126        THE  PROCESSES  OF  PUKE  PHOTOGEAPHY. 

and  dry  it.  As  each  sheet  of  paper  leaves  the  sensitizing 
bath  it  is  blotted  with  clean  blotting-paper,  and  is  immedi- 
ately thereafter  placed  between  two  sheets  of  the  blotting- 
paper  prepared  as  above,  a  weight  placed  on  top  of  the  entire 
lot,  and  in  this  state  the  paper  will  keep  white  and  good  for 
weeks  or  months.  Sheets  of  blotting-paper  similarly  prepared 
may,  with  great  benefit  in  results,  be  used  as  pads  for  the 
printing  frame,  especially  when,  owing  to  bad  light  or  dense 
negatives,  the  printing  is  very  protracted. 

Ready-sensitized  paper  is  an  article  of  commerce  largely 
used,  and  being  more  and  more  used  every  day.  Its  qualities 
are  often  excellent,  and  in  use  it  in  no  way  differs  from 
home  sensitized  albumen  paper.  The  method  of  production 
is  supposed  to  be  a  trade  secret. 

Printing  presents  no  difficulties  to  those  who  have  acquired 
experience.  The  critical  point  is  the  extent  to  which  the 
printing  should  be  allowed  to  go,  and  nothing  but  experience 
will  ever  teach  that.  Papers  differ  and  negatives  differ  in 
this  respect ;  tastes  also  differ.  We  may  say,  however,  that 
with  albumen  paper  the  printing  is  always  to  be  carried 
several  degrees  beyond  the  depth  required  finally,  as  all 
papers  lose  more  or  less  depth  in  the  subsequent  processes  of 
toning  and  fixing.  "  Double  printing,"  "  vignetting,"  and 
other  special  manipulations  are  treated  in  another  chapter 
(page  133,  et  sq.*).  After  the  print  leaves  the  printing  frame 
it  is  placed  aside  in  the  dark,  or  in  safe  light,  till  a  sufficient 
number  are  ready  for  the  next  processes. 

Toning. — The  paper  when  it  leaves  the  printing  frame  is 
still,  of  course,  sensitive  to  light  and  requires  fixing;  but 
were  it  fixed  without  an  intermediate  operation,  the  image 
would  not  only  be  of  a  most  unsightly  color,  but  would  be 
"  fugitive  "  and  fade  in  a  comparatively  short  time.  By  the 
process  of  toning,  or  "  gilding,"  as  it  has  been  aptly  called, 
we  give  the  image  not  only  a  pleasant  color  but  superior  per- 
manence. Toning  consists  of  either  replacing  a  certain  quan- 
tity of  the  reduced  silver  (oxide  ?)  by  gold,  according  to  one 
theory  ;  or  depositing  a  layer  of  gold  over  the  reduced  silver, 
according  to  the  theory  which  appears  better  founded.  The 


THE    PROCESSES    OF    PURE    PHOTOGRAPHY.  127 

gold  is  deposited  from  an  alkaline  solution  of  its  ter-chlorider 
and  the  toning  bath  commonly  used  is  known  as  the  "  alka- 
line gold  toning  "  bath.  The  action  changes  the  color  of  the 
image  from  a  rusty  red  to  brown,  violet,  purple,  or  blue,, 
according  to  the  color  of  the  underlying  substance  seen 
through  the  gold  layer,  and  according  to  the  thickness  and 
state  of  division  of  the  gold  layer.  Thus,  in  order  to  produce 
a  rich,  warm  tone,  it  is  necessary  that  the  image,  before  toning, 
shall  have  a  more  or  less  ruddy  color,  for  it  is  evident  that  if 
on  a  purple  or  violet  ground  we  superpose  a  layer  of  metallic 
gold,  itself  black  or  nearly  so,  we  can  never  produce  a  warm 
blending  of  color.  Thus,  in  the  washing  necessary  previous 
to  toning,  we  should  endeavor  to  produce — if  we  wish  warm 
tones  finally — a  substratum  as  warm  or  ruddy  as  possible, 
Moreover,  the  more  gold  we  can  pile  upon  our  image,  with- 
out giving  the  image  too  much  of  the  cold  color  characteristic 
of  gold  in  fine  division,  the  greater  the  chance  of  permanence 
for  our  image  ;  for  it  is  the  complicated  organic  silver  com- 
pound that  causes  fading,  and  not  the  gold,  as  may  easily  be 
proved  by  comparing  the  action  of  agents  destructive  to  a 
print — as  mercuric  chloride — upon  a  toned  and  an  untoned 
print. 

Following  out  the  above  reasoning,  we  need  have  no  doubt  as 
to  our  operations  in  washing  previous  to  toning.  Some  papers 
leave  the  printing  frame  with  a  ruddy  color,  which  is  accent- 
uated on  washing  in  water.  These  prints  only  require  to  be 
washed  in  plain  water,  till  free  silver  nitrate  is  removed ; 
three  or  four  changes  of  water  suffice,  as  a  rule,  to  remove  the 
silver  nitrate,  the  last  water  should  show  no  sign  of  milki- 
ness,  due  to  the  nitrate,  combined  with  salts,  in  the  water. 
But  these  red  papers  are  usually  acid,  having  been  "preserved  n 
by  a  method  entailing  free  acid ;  and  as  acid  in  the  toning  bath 
is  objectionable,  it  is  advisable  to  put  into  the  second  washing 
water  a  small  quantity  of  sodic  carbonate.  The  prints  must 
not  convey  acid,  nor,  as  a  rule,  carbonates,  to  the  toning-batlu 
Prints  that  leave  the  printing  frame  violet  must  be  reddened 
for  a  warm  tone,  and  to  insure  this  a  quantity  of  sodic  chloride 
(common  salt)  is  put  into  the  second  washing  water;  but 


128  THE    PROCESSES    OF   PUKE   PHOTOGRAPHY. 

neither  should  this  substance  be  allowed  to  get  into  the  toning- 
bath.  During  washing  the  prints  should  be  kept  moving  for 
about  ten  minutes  in  each  "  water,"  and  should  not  be  touched 
on  the  face  with  the  fingers.  After  washing,  the  prints  are 
conveyed  separately  to  the  toning  solution.  The  dish  contain- 
ing this  should  be  white  porcelain,  and  of  sufficient  area  to 
hold  two  prints,  side  by  side,  at  least.  The  solution  should  be, 
at  least,  half  an  inch  deep,  we  prefer  more  depth.  In  the 
"toner"  the  prints  must  be  kept  moving,  and  should  be,  at 
first,  anyhow,  face  down.  • 

Very  many  toning-bath  formulae  have  been  suggested  ;  as  a 
matter  of  fact,  the  mode  of  using  influences  the  results  far 
more  than  the  formulae  used.  The  temperature  should  not  be 
under  65  deg.  Fahr.,  nor  over  75  deg.  Fahr.  We  give  two 
formulae  only,  the  first  is  the  oldest  of  .its  kind,  so  far  as  we 
know,  and  we  are  quite  certain  it  has  never  yet  been  surpassed 
for  beauty  of  action,  certainty,  and  keeping  qualities. 

1.  Sodic  acetate 375  grains 

Water 120  ounces 

Put  a  fifteen  grain  tube  of  "  terchloride  of  gold  "  into  a 
large  bottle,  break  the  tube  in  the  bottle,  and  pour  in  the  above 
solution.  Ready  for  use  after  twenty-four  hours,  or  may  be 
made  ready  sooner  by  using  the  acetate  solution,  boiling  and 
using  the  toning  solution  when  cooled  to  70  deg.  Fahr.  We 
prefer  to  allow  the  twenty-four  hours  to  pass.  This  solution 
will  keep  good  for  any  length  of  time,  provided  the  gold  when 
used  up  by  toning,  is  replenished  by  a  stock  solution,  which 
may  be  made  as  follows : 

Terchloride  of  gold 15  grains 

Water  to 2  ounces 

Each  dram  contains  about  one  grain  gold  chloride,  and  a 
sheet  of  paper  17x22  inches  will  absorb  about  one  grain  of 
gold.  We  take  for  granted  that  the  reader  will  buy  his  "  gold  " 
in  the  hermetically-sealed  glass  tubes  on  the  market.  It  is 
never  pure,  and  seldom  up  to  announced  strength,  but  answers 
the  purpose  when  used  as  above. 

2.  Sodic  biborate  ("borax  ") 60  grains 

Hot  water 10  ounces 

Gold  terchloride. 1  grain 


THE    PROCESSES    OF    PUKE    PHOTOGRAPHY. 


129 


Gives  good,  warm  tones,  but  must  be  used  at  once,  as  it  will 
not  keep.  It  is,  above  all,  important  to  keep  toning  solutions 
alkaline,  distinctly,  but  not  violently,  so,  and  ammonia  will  be 
found  as  suituable  as  any  alkali  for  the  purpose. 

If  the  prints  tone  very  rapidly  to  a  blue  color,  the  gold  is, 
probably,  in  too  great  quantity ;  the  prints  will  lose  their  tone 
in  the  fixer,  and  the  result  will  be  fugitive.  If  the  prints  tone 
unevenly,  the  cause  is  either  acidity,  too  much  gold,  or  too 
high  temperature.  If  patches  refuse  to  tone,  probably  they 
have  been  touched  with  greasy  fingers.  The  toning  should 
take  at  least  ten  minutes,  we  prefer  it  to  take  fifteen  or  twenty. 
The  prints  must  be  kept  in  constant  motion,  and  on  no  account 
be  allowed  to  stick  together,  or  to  the  side  of  the  dish.  The 
prints  should  be  removed  from  the  toner  when  by  transmitted 
light  they  appear  about  the  color  finally  desired  ;  by  reflected 
light  there  will  be  a  trace  of  blue  beginning  to  appear  on  the 
high  lights.  Practice  alone  can  teach  to  what  degree  prints 


Trft 

PECT 

MT&^pRitfJ 

WASHER 


FIG.  23. 

should  be  toned ;  some  workers  tone  by  dull,  diffused  daylight, 
others  prefer  artificial  light.  So  long  as  the  same  kind  of  light 
is  used,  and  the  color  carefully  noted,  it  is  immaterial  what 
light  is  used.  After  toning  is  finished,  the  prints  are  placed 
in  clean  water,  but  unless  a  little  common  salt  is  put  into  this 
water,  toning  is  apt  to  continue. 

Fixing  is  done  in  a  solution  of  sodic  hyposulphite  one  part,  to 
water  fivg  or  six  parts,  and  the  solution  must  be  alkaline,  and 
should  be  about  60  deg.  Fahr.,  certainly  not  cooler.  The 
prints  should  be  moved  about  in  the  fixing  solution  as  in  the 
toning,  and  fifteen  minutes  at  least  should  be  allowed  for  the 


130  THE    PKOCESSES   OF   PUKE   PHOTOGRAPHY. 

fixing.  After  fixing,  the  hypo  must  be  thoroughly  eliminated 
by  washing.  This  is  not  so  easily  effected  as  might  be 
imagined,  for  hypo  sticks  with  great  tenacity  to  textiles  such 
as  paper. 

A  great  many  washing  machines  are  on  the  market,  some 
good,  others  useless.  It  is  important  to  remove  the  hypo  as 
rapidly  as  possible,  for  prolonged  soaking  in  water  injures  the 
prints.  We  advocate  manual  washing  contrivances,  so  far  as 
such  can  be  carried  out.  If  the  print  is  laid  face  downward 
on  a  sheet  of  glass,  a  rose  tap  playing  on  the  back,  and  a 
squeegee  passed  repeatedly  over  the  back  of  the  paper  five  or 
six  times  during  two  minutes,  more  hypo  will  be  removed  than 
by  three  or  four  hours  of  washing  in  any  of  the  washing 
machines  we  know.  Hot  water  removes  a  great  proportion  of 
hypo,  but  if  too  hot,  it  will  alter  the  tone  of  the  print.  If  a 
washing  machine  is  to  be  used,  it  should  be  on  the  "  exit-from- 
the- bottom  "  principle,  as  the  hypo-contaminated  water  sinks ; 
the  prints  must  be  kept  in  constant  motion,  and  a  false  bottom, 
on  which  the  prints  may  drip  at  intervals  is  an  advantage.  The 


FIG.  230. 

old  circular  porcelain  washing-dish  answers  our  description  as 
well  as  any ;  we  use  ourselves  a  large  wash-tub  arranged  on  the 
same  principle.  The  change  of  water  should  be  constant,  and 
its  current  circular,  so  as  to  cause  the  prints  to  keep  traveling 
around  the  machine.  If  running  water  cannot  be  used,  frequent 
changes,  with  intermediate  spongings,  must  be  used  in  default. 
Our  figure  23  shows  a  very  good  washing  machine,  and  23a 
shows  a  rack  for  holding  glass  plates  in  the  same  machine. 

A  sufficiently  accurate  test  for  hypo  remaining  in  a  print  is 
starch  iodide,  prepared  by  adding  to  "  tincture  of  iodine "  a 
little  starch  dissolved  in  boiling  water.  This  will  give  a  dark 
blue  liquid,  to  which  water  is  added  till  the  color  is  very  pale 


THE    PROCESSES    OF    PUKE    PHOTOGRAPHY.  131 

blue.  Touch  the  back  of  the  print  with  blue  solution ;  if  hypo 
is  present  the  blue  will  be  dispelled ;  if  there  is  no  trace  of 
hypo,  the  color  will  remain.  If  a  print  is  'mashed  up  in  water, 
and  the  above  test  made  with  the  water,  the  test  will  be  more 
conclusive. 

The  washing  being  finished,  the  prints  are  dried  between 
sheets  of  pure  blotting-paper,  or  in  any  convenient  way. 
Before  they  are  quite  dry  they  should  be  rolled,  albumen  side 
outward,  round  a  cylinder  of  wood  or  cardboard,  and  kept  so 
till  quite  dry,  they  will  then  leave  the  cylinder  with  a  fine 
surface-gloss. 

Blisters,  large  or  small,  sometimes  appear  on  prints  in  the 
first  water  after  fixing.  Small  blisters  presenting  a  pretty 
hard  surface  usually  disappear  and  do  not  finally  damage  the 
prints.  The  large,  soft  blisters  always  spoil  prints,  and,  once 
they  appear,  seem  to  be  incurable.  To  avoid  both  kinds :  Let 
the  first  water  after  fixing  be  tepid.  Add  a  little  common  salt 
to  the  first  water  after  fixing.  Add  a  little  alcohol  or  ammo- 
nia liquor  (ten  drops  to  each  half-pint  of  fixer)  to  the  hypo 
solution.  If  these  fail  to  prevent  blisters,  which  appear  on 
double  albumenized  paper,  but  not,  within  our  experience,  on 
ordinary  albumen  paper,  wait  for  a  change  of  weather ;  failing 
all  these,  reject  the  sample  of  paper. 

Prints  Yellow,  where  they  ought  to  be  white,  are  produced 
by  keeping  the  paper  too  long  after  sensitized  before  printing, 
or  after  printing  before  toning. 

Metallic  Spots  are  due  to  impurities,  probably  iron,  in  the 
paper,  or  in  the  blotting-paper  used  at  some  stage. 

Bronzed  Shadows  and  Violent  Contrasts,  if  the  negatives 
are  not  at  fault,  point  to  over-strong  sensitizing  bath. 

Want  of  Contrast,  if  not  due  to  the  negative,  is  due  to  a 
weak  sensitizing  bath. 

The  Mounting  of  prints  hardly  comes  within  our  scope ;  we 
shall  confine  ourselves  to  saying  that  the  mounts  must  be  above 
suspicion  of  matter  deleterious  to  the  prints,  and  the  mountant 
or  adhesive  substance  used  must  be  neither  hygroscopic  nor 
liable  to  turn  acid.  India-rubber  solutions  lose  their  adhesive- 
ness after  a  time ;  fresh  starch  solution,  and  gelatine  dissolved 


132  THE   PROCESSES    OF   PURE    PHOTOGRAPHY. 

with  an  antiseptic  such  as  thymol  is  often  used.  Good  glue  seems 
a  favorite  mountant  with  professional  mounters.  Mr.  Alex. 
Cowan's  ingenious  method  of  mounting  dry  is  well  worthy  of 
notice.  Mr.  Cowan  applies  starch  to  the  back  of  the  prints 
when  damp,  and  thereafter  allows  them  to  dry.  He  damps 
the  mount  and  not  the  print — which  obviates  the  distortion 
due  to  stretching  produced  by  wetting  the  print — and  he  lays 
and  arranges  the  dry  print  on  the  dampened  mount,  then  passing 
the  whole  through  a  rolling-press. 

To  Enamel  Prints. — Coat  a  clean  and  talced  glass  plate  (see 
page  106)  with  plain  collodion ;  wash  when  set ;  lay  the  plate 
face  up  in  a  hot  solution  of:  Gelatine  (white),  one  ounce, 
water,  ten  ounces.  Immerse  the  print  face  down  in  the  same 
solution  for  a  moment,  then  bring  plate  and  print  in  contact 
out  of  the  solution ;  squeegee  the  back  of  the  print,  using  a 
rubber  cloth  between  print  and  squeegee.  Avoid  air-bells; 
allow  to  dry.  Cut  round  edges  and  strip.  A  very  high  gloss 
will  be  found  on  the  print,  if  it  was  quite  dry  before  stripping. 

If  it  is  desired  to  mount  the  print,  this  must  be  done  before 
stripping,  by  placing  a  sheet  of  thin  cardboard  at  the  back  of 
the  print  while  it  is  on  the  glass  plate,  and  still  damp  with 
gelatine  solution.  The  cardboard  itself  may  be  laid  for  a  mo- 
ment on  the  gelatine  solution  before  being  placed  in  contact 
with  the  print,  and  to  prevent  the  cardboard  springing  away 
from  the  print,  a  flat  board  may  be  laid  on  the  top  of  the  card 
and  a  weight  placed  on  the  board. 

To  Mount  a  Print  in  "  Optical  Contact"  with  Glass. — 
The  glass  should  be  free  from  scratches  and  as  clear  as  pos- 
sible. It  is  not  talced  nor  collodionized,  but  the  print  is  fast- 
ened to  it  with  gelatine  solution  as  for  the  enameling  process. 

After  prints  on  albumen  paper  (not  enameled)  are  mounted, 
they  are  usually  passed  through  a  hot  "  roller "  or  "  burn- 
isher," in  order  that  they  may  have  a  certain  amount  of  gloss. 

The  process  of  rolling  calls  for  no  remarks. 


CHAPTEK  XXII. 

PREPARATION  OF  NEGATIVES  FOR  PRINTING, 
COMBINATION   PRINTING,   VIGNETTING. 

(Though  many  of  the  remarks  in  this  chapter  apply  to  all 
printing  processes,  we  insert  them  in  this  place  chiefly  on  the 
score  of  convenience  to  our  readers  and  ourselves). 

It  must  not  be  taken  as  a  matter  of  course  that  the  washed 
and  dried  negative  is  there  and  then  ready  for  the  printing 
frame.  In  some  cases  it  may  not  be  capable  of  improvement, 
but  in  many  cases  some  manipulation  is  necessary,  and  in 
most  cases  the  negative  may  be  greatly  improved  by  manipu- 
lation. Leaving  alone  the  vexed  question  of  "  retouching," 
we  may  at  least  point  out  the  immense  value  of  manipulating 
masses  on  the  negative.  Weak  foregrounds  may  be  strength- 
ened, glaring  distances  may  be  toned  down,  balances  of  light 
may  be  introduced,  and  to  the  artistic  eye  many  improve- 
ments may  suggest  themselves  which  may  be  carried  out  by  a 
little  simple  manipulation,  and  against  which  there  is  assuredly 
neither  law  nor  reason.  For  such  purposes  as  these,  besides 
the  processes  of  intensification  and  reduction,  general  or  local, 
already  mentioned,  we  may  suggest  a  few  dodges  that  may  be 
used  for  making  the  best  of  negatives  not  quite  perfect  when 
completed  by  the  processes  already  described. 

To  strengthen  either  locally  or  generally  a  finished  nega- 
tive, a  film  of  a  material  more  or  less  non-actinic  may  be  used. 
For  such  a  purpose  the  plate  may  be  covered  on  the  back 
with  a  coat  of  collodion  or  varnish  containing  a  yellow  dye,  as 
aurantia  ;  the  whole  of  the  back  is  first  coated  in  the  usual 
way,  and  from  the  parts,  if  any,  that  are  dense  enough  the 
film  is  scratched  away.  "Mat  varnish"  may  be  used  in  the 
same  way,  with  the  additional  advantage  that  this  medium 


134  THE   PROCESSES   OF   PURE   PHOTOGRAPHY. 

takes  very  freely  any  ground  pigment,  as  plumbago  applied 
with  a  soft  "stump,"  or  even  with  the  finger,  or  a  pad  of 
wool  or  cloth.  A  formula  for  mat  varnish  is  to  be  found 
among  our  formulae  at  the  end,  but  it  may  be  bought  ready 
made  at  any  dealers.  A  backing  of  any  translucent  or  yellow- 
colored  medium  undoubtedly  causes  the  negative  to  yield, 
with  any  contact  printing  process,  a  print  more  brilliant  than 
without  the  backing  would  be  obtained ;  but,  perhaps,  the 
amount  of  advantage  gained  by  this  proceeding  has  by  many 
been  overrated. 

Printing  in  a  strong  light  certainly  yields  prints  of  less 
vigor  than  printing  in  a  subdued  light ;  hence,  an  over-dense 
or  "  hard  "  negative  should  be  printed  in  sunlight  rather  than 
in  diffused  light,  and  near  a  strong  light  rather  than  a  weak 
one  in  printing  processes  where  artificial  light  is  used.  (There 
are,  however,  exceptions  to  the  latter  part  of  the  last  sentence.) 
A  very  thin,  weak  negative  printed  in  diffused  light,  or  under 
ground-glass  or  tissue-paper  or  yellow  glass,  will  undoubtedly 
yield  a  "  pluckier "  print  than  the  same  negative  printed  in 
the  straightforward  way. 

What  is  called  "double"  or  "combination"  printing  is  in 
some  hands  carried  to  a  point  of  great  excellence ;  we  do  not 
propose  to  deal  with  it  except  in  one  phase — that  of  printing 
clouds  from  a  separate  negative  over  a  view  already  printed 
from  an  ordinary  landscape  or  architectural  negative.  A 
plain,  white  piece  of  paper  intended  to  represent  the  beautiful 
canopy  that  stretches  over  our  heads  in  nature,  is  an  insult  to 
artistic  ideas  seldom  perpetrated  nowadays.  But  incongruous, 
inappropriate  or  impossible  clouds  over  a  landscape  is  an 
.insult  still  more  gross  than  the  white  paper,  and  such  careless- 
ness as  printing  clouds  on  the  top  of  architecture,  trees  or 
hills  is  unpardonable. 

To  make  a  cloud  negative  no  special  process  is  required.  A 
slow  plate  and  a  rapid  exposure  coupled  with  a  fairly  restrained 
developer  will  insure  a  good  cloud  negative.  The  negative 
should  not  be  made  by  any  means  dense,  unnecessary  density 
simply  entails  more  trouble  in  printing.  Of  course,  clouds 
must  be  chosen  of  a  nature  and  in  an  aspect  likely  to  be 


THE    PROCESSES    OF    PUKE    PHOTOGRAPHY.  135 

useful  for  the  purpose  for  which  they  are  intended.  Very 
stormy  clouds  can  very  seldom  be  used,  simply  because  land- 
scapes are  very  seldom  photographed  in  very  stormy  weather. 
Clonds  with  the  sun  right  in  the  middle,  whether  the  sun  is 
seen  or  only  suggested,  will  be  of  use  only  for  landscapes 
taken  with  the  sun  right  in  the  front  of  the  lens,  which  is  a 
matter  of  rare  occurrence.  Clouds  such  as  found  right  over- 
head in  the  zenith  are  not  likely  to  be  appropriate  for  printing 
close  to  the  horizon,  any  more  than  clouds  characteristic  of  the 
ocean  are  likely  to  be  suitable  for  inland  scenery.  Still  more 
emphatically,  clouds  lighted  from  the  left  are  not  adapted 
for  printing  over  a  landscape  lighted  from  the  right,  though 
we  have  seen  a  "gold  medal"  attached  to  a  picture  so  com- 
posed. 

Clouds  are  best  photographed  on  the  level,  if  possible ;  the 
less  the  eminence  from  which  they  are  taken  the  better  as  a 
rule.  But  sometimes  there  is  no  choice. 

If  the  original  sky  of  the  view  negative  print  any  degree 
beyond  a  pale  gray,  the  sky  will  require  to  be  "blocked  out" 
with  opaque  paint  of  some  kind.  A  pale  gray  horizon  over  a 
landscape  is  better  than  a  hard,  chalky  white  for  our  purpose, 
but  anything  darker  than  pale  gray  will  require  blocking  out. 
If  the  gray  is  a  shade  darker  than  it  ought  to  be,  a  cloud 
negative  presenting  considerable  contrast  may  be  chosen, 
provided  it  is  otherwise  suitable.  As  a  rule,  a  very  chalky 
sky  means  an  under-exposed  negative. 

The  blocking  out  may  be  done  on  the  face  of  the  negative 
with  a  solution  as  thick  as  possible  of  vermillion  water-color 
paint  or  India  ink. 

Opaque  material  is,  we  believe,  sold  for  this  and  similar 
purposes.  So  long  as  the  landscape  horizon  presents  a  sharp 
line  there  is  no  difficulty  for  a  steady  hand,  but  if  tree- 
branches  project  into  the  sky  the  operation  becomes  more 
difficult.  Branches  are  best  blocked  out  not  by  straight  lines, 
but  by  "  dabs "  or  stippling  on  the  back  of  the  negative. 
Practice  alone  will  teach  this.  Very  intricate  architectural 
lines  are  often  puzzling,  but  care  and  practice  will  enable 
us  to  block  them  out  perfectly. 


136         THE  PEOCE88ES  OF  PURE  PHOTOGRAPHY. 

In  our  last  chapter  we  showed  the  usual  manipulation  of 
printing  by  contact,  and  the  reader  must  have  a  certain  amount 
of  practice  in  ordinary  printing  before  he  attempts,  or  is  likely 
to  wish  to  attempt,  combination  printing. 

The  landscape  being  printed  by  a  printing-out  process,  and 
visible,  as  in  the  albumen  paper  process,  or  partially  visible,  as 
in  the  platinotype  process,  a  suitable  cloud  negative  is  selected 
and  placed  face  to  face  in  a  suitable  position  with  the  land- 
scape print,  which  has  the  sky  white,  or  nearly  so.  The  two 
are  then  laid  in  a  printing  frame  together,  the  cloud  negative 
undermost,  the  frame  is  then  closed  in  the  usual  way.  If  the 
cloud  negative  be  not  too  dense,  or  the  landscape  sky  not  too 
dark,  the  shape  of  the  cloud  will  be  distinctly  seen  from  the 
front  of  -the  frame,  and  the  horizon  line  of  the  landscape  will 
be  easily  recognized.  The  frame  is  laid  face  up  in  the  usual 
way  for  printing,  and  the  landscape  is  entirely  covered  with  a 
limp  opaque  cloth,  as  velvet.  When  the  horizon  of  the  land- 
scape is  a  sharp  line,  as  of  hills,  fhe  difficulty  is  slight ;  where 
the  outline  is  jagged,  the  operation  requires  more  skill.  To 
avoid  a  hard  line  the  upper  edge  of  the  velvet  must  be  con- 
stantly moved  if  the  printing  is  done  in  sunlight,  frequently  if 
in  diffused  light.  The  cloud  picture  is  to  be  graduated  or 
"vignetted"  down  to  the  landscape.  Where  there  is  a  dark 
mass  already  printed  against  the  sky,  as  in  the  case  of  heavy 
foliage,  the  mass  may  be  practically  disregarded,  as  that  part, 
being  already  dark,  any  clouds  in  the  negative  coming  over  it 
cannot  naturally  be  printed,  the  paper  being  already  printed 
in  these  parts.  Thus,  where  dark  tree-branches  come  against 
the  sky,  the  cloud  may,  in  many  cases,  be  -printed  right  over 
and  branches ;  if  this  is  well  done,  the  result  is  very  natural 
the  satisfactory. 

"  Vignetting,"  or  graduating  the  margins  of  the  picture 
instead  of  printing  the  subject  dark  to  the  edge,  is  performed 
in  various  ways.  Glasses  are  sold  with  their  centre  white,  and 
graduated  in  an  oval  or  pear  shape  to  a  red  edge.  When  these 
are  well  made  they  give  a  very  good  vignette.  The  usual 
way,  however,  is  to  cut  out  of  a  piece  of  cardboard,  sheet  lead, 
zinc,  wood,  or  other  opaque  material,  an  opening  of  the  desired 


THE  PROCESSES  OF  PUEE  PHOTOGRAPHY. 


137 


shape  and  approximately  the  desired  dimensions.  The  inner 
edges  of  the  "  masks "  are  serrated  and  the  printing  is  done 
with  the  mask  an  inch  or  two  in  front  of  the  negative.  A 
piece  of  tissue-paper  is  usually  placed  over  the  aperture  in  the 
mask  to  insure  better  gradation.  Yignette  printing  is  done  in 
diffused  light,  and  the  further  the  mark  is  away  from  the 
negative  the  softer  the  gradation.  The  "vignette"  is  a  style 
highly  popular  for  portraiture,  and  is  well  suited  to  many 
landscapes,  though  much  less  used  for  that  class  of  subject. 


FIG.  24. 


We  figure  an  arrangement  that  will  enable  one  to  produce  and 
to  vary  vignettes  almost  at  will,  and  with  a  very  little  practice. 


CHATER  XXIII. 
PRINTING   OF    PLAIN  SALTED  PAPER. 

THIS  is  an  old  process,  which  has,  unfortunately,  gone  some- 
what out  of  use  of  late  years ;  but  none  the  less  beautiful 
results  can  be  got  with  it,  and  though  it  seems  difficult  to  get 
a  certain  class  of  tone — engraving  black,  or  very  dark  blue — 
still  if  the  process  were  worked  by  many  persons,  there  would 
be  a  chance  of  some  one  lighting  on  a  system  by  which  per- 
fect tones  of  the  desired  kind  could  be  obtained.  As  it  is, 
very  beautiful  tones  can  be  got,  and  we  hope  to  see  the  pro- 
cess receive  more  attention  in  the  future  than  in  late  years. 

The  paper  used  for  albumenizing  is  eminently  suited  for 
this  process,  but  any  good  wove  paper  will  answer  the  purpose. 
It  must  be  sized  and  salted.  A  formula  found  in  '•  Hardwich's 
Photographic  Chemistry,"  5th  edition,  page  311,  will  suit  all 
purposes.  The  paper  (Saxe)  is  floated  upon  the  following 
solution : 

Ammonium  chloride 60  grains 

Gelatine 20  grains 

Water 20  ounces 

Dissolved  by  heat  and  filtered  when  cold. 

Mr.  Otto  Scholzig,  of  London,  favors  us  with  a  "size," 
which  will  be  found  splendid  for  an  ordinary  silver  nitrate 
sensitizing  bath.  The  ammonia-nitrate  bath,  which  is  recom- 
mended later,  may  dissolve  the  albumen,  though  in  our  hands 
it  did  not  do  so. 

Sodic  chloride 250  parts 

Citric  acid 10  parts 

Irish  moss 50  parts 

Gelatine 20  parts 

Albumen 500  parts 

Water 2000  parts 


THE   PROCESSES   OF   PURE   PHOTOGRAPHY.  139 

The  paper  having  been  floated,  face  downward,  on  one  of 
the  above  sizing  and  salting  baths,  is  hang  up  to  dry.  The 
back  of  the  paper  may  be  recognized  by  the  faint  "crapy" 
marks  due  to  the  gauze  on  which  the  paper  is  laid  to  dry  after 
its  manufacture. 

The  sixty  grain  bath  of  silver  nitrate  as  given  for  albumen 
paper  will  answer  equally  well  for  this  paper. 

Paper  sized  by  our  first  formula  (Hardwich's)  may  be  sen- 
sitized on  an  ammonia-nitrate  bath.  A  sixty  grain  solution  of 
silver  nitrate  is  taken  and  "  converted "  as  described  on 
page  61.  Other  operations  are  the  same  as  for  albumenized 
paper.  After  the  plain  silver  nitrate  bath,  the  paper  may  be 
floated,  when  only  surface  dry,  face  upward,  on  a  bath  of 
citric  acid  five  parts,  water  one  hundred  parts.  This  will  pre- 
serve it  for  a  long  time. 

With  plain  paper  the  printing  has  to  be  considerably  deeper 
than  with  albumen  paper.  Washing  is  conducted  on  the  same 
principles ;  the  ammonia-nitrate  paper  will  probably  require 
salt  in  the  washing  water. 

Any  good  toning  solution  will  answer  for  plain  paper,  but 
to  get  fine  tones,  as  nearly  as  possible  approaching  black,  the 
following  toning  bath  is  recommended. 

Sodic  tungstate 20  grains 

Sodic  phosphate 20  grains 

Boiling  water 3  ounces 

Dissolve  and  add 

Gold  terchloride 1  grain 

Allow  to  cool,  then  add 

Water 5  ounces 

The  toning  and  fixing  bath  given  as  a  toner  for  gelatine 
chloride  paper,  in  next  chapter,  will  also  answer  admirably  for 
plain  salted  paper. 


CHAPTER  XXIY. 
GELATINE-CHLORIDE    PAPER   FOR    PRINTING-OUT. 

Paper  coated  with  an  emulsion  of  silver  chloride  in  gelatine, 
in  the  presence  of  a  certain  proportion  of  an  organic  silver . 
salt,  has  found  its  way  on  to  the  English  market.  This  class 
of  paper  will  be  found  highly  suitable  for  certain  negatives 
and  certain  effects.  Though  the  papers  have  reached  us  under 
two  names,  the  preparation  and  qualities  seem  to  be  practically 
the  same,  certainly  the  same  treatment  answers  both  samples. 
Very  thin  negatives  will  be  found  to  give  better  results  on 
these  gelatine  chloride  papers  than  on  albumen  or  plain  salted 
paper ;  and  with  very  little  trouble  a  very  high  gloss  can  be 
given  to  the  finished  prints.  When  so  glazed  the  paper 
renders  shadow  detail  in  a  remarkably  perfect  manner. 

The  printing  is  done  by  contact  in  the  usual  way,  printing 
being,  if  anything,  rather  more  rapid  than  with  albumen  paper. 

The  toning  bath  recommended  for  Dr.  Liesegang's  gela- 
tine-chloride paper  is  his  own. 

Water  24  ounces 

Sodic  hyposulphite 6  ounces 

Ammonium  sulpho-cyanide 1  ounce 

Saturated  solution  of  potash  alum 2  ounces 

Dissolve,  place  in  this  solution  some  scraps  of  gelatine-chlor- 
ide paper  for  twenty-four  hours.  Filter,  and  add  : 

Water 6  ounces 

Gold  terchloride 15  grains 

Ammonium  chloride 30  grains 

This  bath  tones  and  fixes  at  the  same  time.  No  washing  is 
required  previous  to  immersion  in  this  bath,  nor  fixing  after 
it.  The  color  during  progress  of  toning  must  be  judged  by 
transmitted  light;  reflected  light  is  here  no  criterion. 


THE    PROCESSES    OF   PURE    PHOTOGRAPHY.  14:1 

Herr  Obernetter's  paper  will  probably  be  found  to  work 
better  with  the  following  toning  bath,  followed  by  the  usual 
fixation  in  hypo  : 

Ammonium  sulpho-cyanide 140  grains 

Sodic  phosphate 140  grains 

Sodic  tungstate 100  grains 

Water 24  ounces 

Dissolve,  place  in  the  solution  scraps  of  the  paper  as  before, 
filter  and  then  add : 

Gold  terchloride 15  grains 

Water 4  ounces 

Examine  during  toning  by  transmitted  light  (i.e.,  by*  looking 
through  the  print)  and  tone  to  a  fine  rich  brown  or  a  purple 
blue,  as  desired.  A  solution  of  hypo  one  part,  in  water  ten 
parts,  is  strong  enough  for  fixing.  After  fixing  and  washing, 
the  prints  may  be  allowed  to  dry  hanging  up  (not  between 
sheets  of  blotting  paper),  in  which  case  they  will  have  a  good 
medium  surface ;  or  they  may  be  squeegeed  to  talced  glass  and 
stripped  when  dry,  when  they  will  have  a  very  high  gloss. 


CHAPTER  XXY. 

CONTACT  PRINTING  ON  GELATINE-BROMIDE 
PAPER. 

This  fine  process  has,  during  the  last  few  years,  thanks  in  a 
great  measure  to  the  perfection  to  which  it  has  been  brought 
by  certain  firms,  gained  a  firm  hold  on  public  esteem.  Certain 
marked  and  undeniable  qualities  in  the  product  turn  the  bal- 
ance strongly  in  favor  of  this  process,  as  compared  with  all  other 
processes  where  silver  salts  are  used.  There  is  no  free  silver 
nitrate  to  form  suspicious  or  objectionable  compounds  with 
organic  substances  ;  gelatine  is  safer  in  the  matter  of  sulphur 
compounds  than  albumen,  even  were  free  silver  nitrate  present 
to  combine  with  the  gelatine.  The  rapidity  with  which  a 
single  print,  or  a  "  long  number  "  of  prints  may  be  produced,  is 
far  beyond  that  of  most  other  processes.  The  latitude  in  quality 
of  negatives  is  far  greater  with  this  process  than  any  other,  a 
good  print  may  be  made  from  a  negative  practically  unprint- 
able by  any  other  process  ;  lastly,  the  results  are  in  artistic 
quality  inferior  to  no  process  of  pure  photographic  printing  at 
present  known.  The  chief  disadvantage  of  the  process  is — 
and  it  is  a  serious  one — that  the  image  is  invisible  until  devel- 
oped, so  that  no  combination  printing  can  be  effected  without 
rather  intricate  and,  at  the  best,  uncertain  operations  and  appar- 
atus. It  may  also  be  put  down  as  a  failing  that  the  progress 
of  printing  is  invisible  and  that  some  experience  is  required 
before  even  decent  results  are  obtained,  but  those  who  have 
had  a  little  practice  will  probably  spoil  as  few  sheets  of  paper 
by  this  process  as  by  any  other. 

A  good  sample  of  bromide  paper  is  coated  with  a  very  thin 
layer  of  fairly  rapid  emulsion,  containing  a  large  proportion 
of  the  silver  haloid.  The  thin  layer  is  necessary  to  prevent 


THE    PROCESSES    OF    PUKE    PHOTOGRAPHY.  14:3 

the  paper  from  curling  in  aqueous  solutions,  and  the  large 
proportion  of  silver  is  needed  to  give  pluck  to  the  very  thin 
film.  On  account  of  the  thinness  of  the  film,  and  in  spite  of 
the  large  quantity  of  silver  in  the  film,  it  will  be  found  that 
there  is  but  little  "  latitude  "  in  exposure ;  and  timing  must  be 
pretty  nearly  correct  for  our  developer,  or  we  shall  fail  to  pro- 
duce a  satisfactory  result.  But  a  little  practice  and  care  will 
enable  the  worker  to  judge  almost  by  intuition  the  exposure 
necessary  for  any  particular  negative,  provided  that  the  light  used 
be  always  the  same  in  actinic  quality  and  visual  intensity.  On 
account  of  this  important  proviso  artificial  light  is  to  be  strongly 
recommended,  if  not  insisted  upon.  It  does  not  much  matter 
what  the  radiant  is,  provided  the  light  be  constant  and  equa[ 
at  all  times.  An  oil  lamp,  always  turned  up  to  the  same  point, 
or  a  "  regulating "  gas  burner  will  be  found  most  suitable. 
Another  point,  which,  if  disregarded  will  introduce  even  more 
uncertainty  and  risk  of  failure  than  the  light,  is  the  distance 
from  the  light  to  the  negative.  Here  the  oft-quoted  law  comes 
in,  that  the  intensity  of  light  varies  inversely  as  the  square  of 
the  distance  from  the  radiant  to  the  recipient.  If  the  correct 
exposure  at  two  feet  be  twenty  seconds,  at  eight  feet  it  will  be 
three  hundred  and  twenty  seconds,  not  eighty  seconds,  as  some 
may  suppose.  Or  if  the  correct  exposure  at  two  feet  be 
twenty  seconds,  and  if,  by  mistake,  we  expose  at  three  feet 
instead  of  two  feet,  we  shall  under  expose  just  two  and  a  half 
times,  as  22  :  32  : :  20  :  45,  forty-five  seconds  being  the  expos- 
ure required  at  three  feet  to  correspond  with  twenty  seconds 
at  two  feet. 

Kegarding  exposure,  a  few  general  rules  may  be  useful,  but 
it  must  be  remembered  that  they  are  general,  and  have  excep- 
tions : 

The  denser  the  negative  the  more  the  exposure  required, 
and  vice  versa.  Practically  this  has  no  exception. 

Long  exposure  leads  to  softness,  harmony,  flatness. 

Short  exposure  tends  to  brilliance,  pluck,  hardness. 

Strong  development  gives  pluck,  contrast,  hardness. 

Weak  development  gives  harmony,  softness,  effeminacy. 

Strong  restrainers  lead  to  pluck,  brilliance,  hardness,  bad 
color  and  want  of  detail. 


144        THE  PROCESSES  OF  PURE  PHOTOGRAPHY. 

These  rules  do  not  cover  all  circumstances ;  for  instance,  a 
long  exposure  coupled  with  a  too  strong  developer  would  give 
flatness  or  fog  in  place  of  brilliance ;  but,  given  two  prints  of 
the  same  negative  equally  and  normally  exposed,  a  strong 
developer  will  yield  a  pluckier  image  than  a  weaker  developer. 

The  standard  or  stock  solutions  for  ferrous  oxalate  developer 
are  saturated  solutions  of  ferrous  sulphate  and  potassic  oxalate 
as  given  on  page  91.  As  a  rule  the  iron  solution  should  bear 
a  less  proportion  to  the  potassic  oxalate  solution  for  bromide 
prints  than  for  development  of  negatives.  And  a  small  pro- 
portion of  soluble  bromide  is  to  be  recomeuded  for  develop- 
ment of  bromide  prints.  A  strong  normal  solution  may  be 
prepared  thus : 

A.  Potassic  oxalate  saturated  solution 4  ounces 

Potassic  bromide,  10  per  cent,  solution 25  minims 

Iron  sulphate,  saturated  solution 1  ounce 

A  weak  normal  solution  : 

B.  Potassic  oxalate,  as  above ,   Bounces 

Potassic  bromide,  as  above   25  minims 

Iron  sulphate,  as  above 1  ounce 

A  very  weak  solution  : 

C.  B  solution ....  2  ounces 

Water 2  ounces 

We  are  now  in  a  position  to  put  into  practice  the  principles 
laid  down  in  the  last  page  or  two.  If  we  have  an  average 
density  negative  we  may  make  from  it  a  plucky,  brilliant  print 
by  infra-normal  exposure  and  sharp  development ;  or  we  may 
give  our  print  a  soft,  harmonious  character,  by  full  exposure 
and  a  developer  such  as  B.  A  "  ghostly  "  negative,  such  as 
would  be  unprintable  by  any  other  process,  may  be  exposed 
behind  a  sheet  of  ground  or  opal  glass,  the  exposure  being  kept 
down  and  developer  A  being  used,  a  little  extra  bromide  being 
added  if  required.  A  "  chalk  and  soot "  negative  will  be  best 
treated  by  very  prolonged  exposure  followed  by  a  weak  devel- 
oper as  B,  or  in  aggravated  cases,  by  a  watery  developer  as  C. 

When  the  exposure  has  been  too  short,  a  trace  of  sodic 
hyposulphite  may  be  added  to  the  ferrous  oxalate  developer ; 
but  it  must  be  only  a  trace,  and  at  the  best  it  is  a  dangerous 


THE   PROCESSES    OF    PUKE    PHOTOGRAPHY.  14:5 

experiment,  and  one  we  do  not  recommend.  It  will  be  found 
better  to  make  a  fresh  exposure,  putting  the  spoiled  sheet  of 
paper  among  the  residues. 

After  development,  which  must  not  be  carried  too  far,  the 
paper  should  be  washed  in  acidulated  water,  not  in  plain 
water,  least  of  all  in  ordinary  tap  water  containing  lime. 
Half  an  ounce  of  acetic  or  citric  acid  added  to  a  quart  of 
water  will  be  found  sufficient ;  the  quantity  does  not  matter 
so  long  as  the  reaction  is  acid  and  the  acidity  not  strong 
enough  to  damage  the  gelatine.  After  two  or  three  rinsings 
in  acidulated  water,  which  enables  the  iron  to  be  washed  out, 
the  print  is  washed  in  plain  water  so  that  acidity  may  not  be 
communicated  to  the  fixing  bath,  which  is  the  usual  solution  of 
sodic  hyposulphite  alkalized  and  requiring  no  special  remark. 

The  ferrous  oxalate  developing  solution  may  be  used  re- 
peatedly while  fresh ;  by  certain  workers  a  previously  used 
solution  is  stated  to  give  the  best  results.  We  have  not  been 
able  to  verify  this  statement,  and  this  practice  introduces  an 
element  of  uncertainty  which,  for  beginners,  might  prove  puz- 
zling. 

The  hydrochinon  developer  has,  in  our  hands,  with  East- 
man's bromide  paper,  given  the  very  finest  results,  and  we 
recommend  this  developer  especially  for  beginners  ;  provided 
the  exposure  has  been  sufficient  and  not  outrageously  over- 
done, the  action  of  the  developer  is  so  even  that  nothing  but 
attention  is  required  to  stop  development  at  the  proper  stage 
in  order  to  obtain  grand  results.  The  formula  given  is  prac- 
tically that  given  by  Mr.  B.  J.  Edwards  for  lantern-slide 
plates. 

Mix  in  the  following  order : 

Sodic  sulphite  2  ounces 

Water 20  ounces 

Hydrochinon 30  grains 

Sodic  carbonate,   "pure,"  but  not  "dried" Bounces 

Potassic  carbonate 3  ounces 

Potassic  bromide 40  grains 

There  may  be  a  difficulty  in  causing  solution  of  all  these  in 
the  water  unless  the  water  is  hot.  The  water  may  be  divided 


146  THE    PROCESSES    OF    PURE    PHOTOGRAPHY. 

into  two  quantities,  the  sodic  sulphite,  hydrochinon,  and  bro- 
mide being  dissolved  in  one  part,  the  other  salts  in  the  other 
part  of  the  water.  The  solutions  in  this  state  will  keep  a  long 
time  and  may  be  mixed  -  in  equal  parts  for  nse.  But  the 
hydrochinon  must  be  reasonably  fresh  when  dissolved,  as  it 
does  not  keep  very  long.  When  over-kept  it  acquires  an  un- 
healthy brown  appearance  in  the  dry  state. 

Sepia  or  brownish  tones  may  be  obtained  by  alkaline  pyro 
development,  though  no  very  great  measure  of  success  has  as 
yet  attended  this  system.  The  following  will  be  found  fairly 
suitable  : 

Pyrogallol 1  to  2  grains 

Water,  with  a  trace  of  citric  acid '. 1  ounce 

Ammonia .'.... 2  minims 

Bromide 3  grains 

The  prints  must  remain  in  the  fixing-bath  of  hypo  one  part, 
water  five  parts,  alkalized,  for  about  fifteen  minutes,  and  on 
being  put  into  this  bath,  they  must  be  immersed  at  once,  and 
not  unevenly  acted  upon  by  the  hypo.  The  time  allowed  for 
fixation  must  be  ample,  and  the  solution  must  be  alkaline, 
otherwise  the  claim  for  permanence  of  result  will  surely  be 
falsified. 

The  manipulations  of  development  call  for  few  remarks ; 
the  prints  should  be  soaked  in  clean  water,  air-bells  being 
removed  before  development.  This  is  simply  to  make  them 
lie  flat  in  the  developing  dish,  which  should  be  flat,  and, 
preferably,  white.  In  all  cases  where  the  ferrous  oxalate 
developer  is  used,  the  iron  solution  is  to  be  poured  into  the 
oxalate.  If  it  is  desired  to  keep  the  mixed  solution,  the  bottle 
figured  and  described  on  page  may  92  be  used. 

Washing  and  Drying  Bromide  Prints. — The  same  prin- 
ciples as  we  stated  for  washing  albumen  prints  hold  good  here. 
Washing  machines  may  be  used,  but  are  inferior  to  manual 
labor,  and  the  use  of  the  rose-tap  and  squeegee.  (See  page  130.) 
If  any  trace  of  discoloration  of  the  high,  lights  be  observed 
after  fixing  and  washing,  the  prints  may  be  immersed  in 
a  saturated  solution  of  alum  with  a  little  hydrochloric  acid. 
After  this  they  must  again  be  carefully  washed.  If  blisters 


,THE    PROCESSES    OF    PURE    PHOTOGRAPHY.  147 

occur  after  fixing,  a  little  common  salt  added  to  the  first  wash- 
ing-water will  prevent  a  recurrence. 

Bromide  papers  are  sold  usually  in  three  qualities  :  No.  1, 
a  fine  paper  with  a  smooth-surfaced  film ;  No.  2,  a  lieaviei 
paper  with  a  smooth  surface  ;  No.  3,  a  heavy  paper  with 
a  rough  surface.  Prints  on  No.  3  should  be  allowed  to  dry 
spontaneously  ;  those  on  Nos.  1  and  2,  if  dried  spontaneously 
will  have  a  very  good  smooth  surface,  but  if  squeegeed  to 
talced  glass  or  polished  ebonite,  and  stripped  when  dry,  will 
have  a  high  gloss.  To  produce  a  very  high  glaze,  a  talced 
plate  may  be  collodionized  and  washed,  and  used  as  given 
elsewhere. 

Mr.  H.  Senier,  of  London,  England,  has  produced  warm 
tones  in  bromide  prints  by  developing  the  prints  after  exposure 
in  the  usual  way  with  ferrous  oxalate,  then  bleaching  the 
image  out  with  chlorine  water  and  re-developing  in  daylight 
with  ferrous  oxalate. 

Bromide  prints  may  be  mounted  by  appplying  to  the  back 
while  they  are  drying  on  their  ebonite  or  glass  support  sheets 
of  thin  cardboard,  the  mountant  being  starch,  to  which 
Messrs.  Fry  &  Co.,  of  Richmond,  recommend  the  addition  of 
a  small  quantity  of  lump  sugar. 

Opal  plates  bearing  gelatine-bromide  emulsion  for  this  pur- 
pose may  be  treated  in  the  same  way  as  paper. 

The  last  outcome  of  Eastman  ingenuity  is  a  process  called 
"  Transferotype."  This  is  simply  a  stripping  film  of  gelatine- 
bromide  emulsion  suitable  for  printing.  The  film  of  emulsion 
is  said  to  be  not  over  one  five-thousandth  of  an  inch  thick. 
The  prints  are  developed  in  the  usual  way.  After  washing 
they  are  squeegeed  to  opal  plates  prepared  to  retain  the  film 
permanently ;  the  paper  is  removed  by  hot  water,  and  the 
result  is  an  opal  positive  of  a  quality  that  only  requires  to  be 
seen  in  order  to  be  appreciated.  In  this  process  two  things 
are  to  be  guarded  against — over-exposure  and  over-develop- 
ment. (See  remarks  on  Transferotype  for  Lantern -Slides, 
page  180.) 


CHAPTER  XXVI. 
RAPID  PRINTING  PAPER. 

ABOUT  1884  or  1885,  a  printing  process  was  introduced, 
which  came  to  be  called  the  "  rapid  printing  process,"  because 
it  was  more  rapid  than  the  printing-out  processes  com- 
monly used  at  that  time.  The  paper  is  coated  with  very  slow 
gelatine  bromide,  or  chloride,  or  chloro-bromide  emulsion. 
The  exposure  is  very  long  compared  with  other  silver  printing 
processes  by  development,  and  development  produces  a  red 
image  amenable  to  toning. 

A  bright  yellow  light  may  be  used  in  the  operating  room,  and 
exposure  may  be  one  or  two  seconds  to  daylight,  or  several 
minutes  to  artificial  light.  As  a  rule,  the  printed  instructions 
mislead  the  worker  into  giving  too  short  exposures. 

The  developer  may  be  ferrous  oxalate,  very  weak,  and  con- 
taining chloride,  and  sometimes  a  citrate.  The  following  will 
serve  as  an  example. 

a.  Potassic  oxalate 2  ounces 

Ammonic  chloride 40  grains 

Water 20  ounces 

b.  Ferrous  sulphate 4  drams 

Citric  acid 2  drams 

Water 20  ounces 

c.  Ammonic  bromide 1  ounce 

Water  to 4  ounces 

DEVELOPER. 

a 1  ounce 

b 1  ounce 

c 2  drams 

Before  development  soak  in  water  till  the  prints  lie  flat,  and 
care  must  be  taken  not  to  over-develop.  To  prevent  develop- 


THE    PROCESSES    OF    PURE    PHOTOGRAPHY.  149 

ment  going  on  after  the  prints  are  removed  from  the  developer, 
they  are  put  into  water  containing  a  good  dose  of  common  salt. 
A  black  tone  after  development  proves  insufficient  exposure, 
and  will,  of  course,  prevent  toning.  After  several  changes  of 
water,  the  prints  are  put  into  a  concentrated  solution  of  potash, 
alum,  and  again  washed,  after  which  they  are  toned  in 

Sodic  acetate. 30  grains 

Lime  chloride  (fresh) 3  grains 

Gold  terchloride 1  grain 

Water 5  ounces 

After  toning,  the  prints  being  washed,  are  fixed  in  a  one  to 
ten  alkaline  hypo  solution. 

The  prints  may  be,  as  suggested  by  Mons.  Warnerke,  toned 
and  fixed  in  one  bath.  To  do  this,  make  the  fixing-bath  one 
to  three,  and  add  to  every  five  ounces,  one  grain  gold 
terchloride. 

The  prints  may  be  dried,  squeegeed  to  talced  glass,  or  al- 
lowed to  dry  in  the  ordinary  way. 


CHAPTEK   XXYII. 
PLATINOTYPE  OR  PRINTING  IN  PLATINUM. 

THIS  process  is  one  daily  gaining  ground  in  public  favor, 
and  not  without  reason,  for  not  only  are  the  results  of  a  beau- 
tiful and  artistic  character,  but  the  process  carries  with  it  a 
prospect  of  permanence  almost  beyond  the  scope  of  reason- 
able doubt.  This  must  not  be  taken  to  mean  that  a  platino- 
type  print  is  indestructible  as  to  the  image  any  more  than  as  to 
the  paper;  but  it  may  safely  be  asserted,  and  by  one  of  the 
writers  it  has  been  tolerably  clearly  proved,  that  only  tests 
utterly  unlikely  to  occur  in  the  ordinary  treatment  of  any 
print  will  spoil  or  even  affect  a  properly  prepared  platinotype 
print.  The  prints  have  a  character  in  the  shadows  not  vouch- 
safed to  other  processes  of  photographic  printing,  and  the 
manipulations  though  requiring  care  in  certain  respects  are 
perfectly  simple.  The  chief  disadvantage  of  the  process,  if 
it  is  a  disadvantage,  is  that  the  negatives  to  be  printed  require 
to  be  of  something  rather  better  than  average  quality,  a  long 
range  of  gradation  being  almost  a  conditio  sine  qua  non  for  a 
good  print. 

The  image  is  composed  of  platinum  presumably  in  the 
metallic  state.  The  process  was  invented  by  Mr.  "W.  Willis, 
Jr.,  of  London,  and  is  protected  by  letters  patent  in  England 
and  in  America ;  a  license  is  granted  on  nominal  terms  for 
working  the  process,  and  the  materials  requisite  are  supplied 
by  the  Platinotype  Company.  Indeed,  it  is  little  probable  that 
anyone  not  an  experienced  chemist  would  be  able  to  produce 
the  chemicals  himself,  and  even  the  paper  has  to  be  prepared 
in  a  special  manner.  The  most  complete  work  on  the  subject 
is  by  Pizzighelli  and  Hiibl.  ("Platinotype,''  by  Capt.  Piz- 
zighelli  and  Baron  A.  Hiibl,  translated  by  the  late  J.  F. 


THE    PROCESSES    OF   PUBE    PHOTOGRAPHY.  151 

Iselin,  M.A.,  and  edited  by  Capt.  W.  de  W.  Abney,  R.E., 
F.R.S.  London  :  Harrison  &  Son,  59  Pall  Mall.) 

Organic  ferric  salts  are  by'light  reduced  to  the  ferrous  state, 
and  these  ferrous  salts  in  solution  reduce  to  the  metallic  state 
certain  metallic  salts,  notably  those  of  platinum.  Paper 
treated  with  ferric  oxalate  and  potassic  chloro-platinite  is 
exposed  dry  to  light.  The  ferric  oxalate  becomes  ferrous 
oxalate,  which  is  soluble  in  potassic  oxalate  in  solution.  The 
exposed  paper  being  treated  with  a  solution  of  potassic  oxalate 
the  ferrous  oxalate  is  dissolved,  the  potassic  chloro-platinite  is 
reduced,  and  metallic  platinum  is  deposited  in  very  fine 
division,  its  color  in  that  state  being  black.  The  amount  of 
platinum  reduced  is  proportionate  to  the  amount  of  light- 
action. 

Evidently  this  is  a  development  process ;  it  is  also  to  a 
certain  extent  a  printing-out  process,  for  the  printed  image  is 
partially  visible  before  development,  and,  as  shown  later,  the 
process  may  be  worked  as  one  entirely  of  printing-out.  The 
following  important  consideration  should  noticed.  In  a  print- 
out process  the  reduction  to  the  metallic,  or  at  least  to  the 
visible  state,  takes  place  absolutely  in  situ  /  as  the  light 
action  proceeds  the  deposit  is  piled  up  in  the  shadows ;  in  a 
development  process  such  as  we  are  describing,  the  salt  is 
being  dissolved  as  the  metal  is  being  deposited,  so  that  we 
may  look  for  less  "  blocking  up  "  in  the  shadows  where  the 
reduction  is  most  energetic.  We  are  informed  on  the  best 
authority  that  a  platinum  printing-out  process  was  worked  as 
early  as  1873,  but  rejected  on  account  of  this  very  blocking 
up  of  the  shadows. 

The  Practice  of  the  Process. — The  paper  for  platinotype 
printing  may  be  bought  ready-sensitized,  in  which  state  under 
conditions  to  be  stated  presently,  it  will  keep  good  for  a  long 
time — for  a  month,  at  least.  The  necessary  conditions  for 
keeping  the  paper  are  :  Protection  from  actinic  light  and  pro- 
tection from  damp.  The  prepared  paper  is  in  a  high  degree 
hygroscopic,  and  the  slightest  excess  of  damp  to  the  paper  will 
ruin  it.  To  preserve  the  paper  from  both  light  and  damp,  a 
"  calcium  tube  "  is  used.  This  is  a  cylinder  of  metal,  capped 


152  THE    PROCESSES   OF   PDEE    PHOTOGRAPHY. 

at  each  end,  and  in  one  of  the  caps  or  lids  is  a  perforated 
chamber  containing  caleic  chloride,  which  attracts  to  itself  all 
moisture,  and  so  keeps  the  paper  dry.  Usually  asbestos  is  im- 
pregnated with  the  calcic  chloride,  and  when  after  a  time  the 
asbestos  becomes  a  damp  mass,  it  is  put  on  an  iron  shovel  or 
plate  over  a  fire  and  the  damp  driven  off  by  heat. 

The  Company  also  sell  the  paper  and  the  sensitizing  mate- 
rials separately,  and  this  is  useful  for  those  who  work  the  pro- 
cess on  a  very  large  scale  or  only  on  rare  occasions.  Moreover, 
by  varying  the  proportions  of  sensitizing  ingredients,  better 
results  may  be  got  from  negatives  of  varying  qualities. 

The  platinum  salt  is  sold  in  the  solid  form,  the  iron  as  two 
separate  solutions,  which  are  to  be  mixed  in  various  propor- 
tions. We  do  not  know  the  precise  constitution  of  these  two 
solutions,  which  are  simply  marked  "  A  "  and  "  B,"  so  we  can 
only  quote  from  the  Company's  printed  instructions.  By 
increasing  the  proportion  of  "  A  "  to  "  B,"  half  tone  is  lessened, 
so  that  a  large  proportion  of  "  A  "  is  suitable  for  weak,  thin 
negatives.  Vice  versa,  increasing  -the  proportion  of  "B," 
gives  a  solution  more  suitable  for  hard  negatives.  An  average 
mixture  may  be : 

A 1  part 

B 5  parts 

Of  such  a  mixture  1  ounce  may  be  used  to  dissolve  60  grains 
of  the  dry  "  platinum  salt,"  but  this  complete  sensitizing  mix- 
ture will  not  keep  above  half  an  hour,  and  in  hot  weather  not 
above  ten  minutes.  On  no  account  must  heat  be  applied  to 
effect  solution,  stirring  with  a  glass  rod  being  sufficient  to 
cause  solution  of  the  platinum  salt.  The  paper  is  pinned  to  a 
flat  board,  and  the  sensitizing  solution  quickly  spread  over  the 
paper  with  a  perfectly  clean  sponge  or  pad  of  flannel.  For 
each  square  foot  of  paper  about  80  minims  of  sensitizing  solu- 
tion will  be  required.  The  solution  is  poured  right  on  the 
middle  of  the  paper,  and  immediately  spread  over  the  whole 
surface.  It  may  be  necessary  to  work  in  dull  daylight,  as  by 
yellow  light  it  is  difficult  to  see  to  spread  the  yellow  solution 
properly,  but  each  sheet  when  coated  must  be  at  once  removed 
to  non-actinic  light,  and  the  sponge  or  pad  must  be  frequently 


THE   PROCESSES   OF    PUKE   PHOTOGRAPHY.  153 

washed.  Platinotype  paper  is,  in  the  first  place,  much  more 
sensitive  to  light  than  alhumen  paper  (as  two  or  three  to  one), 
and  in  the  next  place,  light  hurts  platinotype  paper  more 
than  albumen  paper,  for  any  slight  veil  contracted  by  the 
latter  before  toning  is  removed  by  the  toning  and  fixing-baths, 
which  is  not  the  case  with  platinotype  paper,  with  which  there 
is  no  analogous  "  clearing  "  action.  Platinotype  paper  should 
be  dried  in  a  room  with  a  stove  or  open  fire,  and  the  room 
must  be  lighted  non-act inically,  if  at  all ;  the  drying  should  be 
arranged  so  as  to  take  about  ten  minutes.  When  apparently 
dry,  the  paper  should  be  held  near  the  fire  for  a  minute  to 
drive  off  all  trace  of  moisture.  It  is  then  placed  in  a  calcium 
tube  and  kept  absolutely  dry.  Damp  is  probably  by  far  the 
most  frequent  cause  of  failure  with  this  process. 

Printing  is  performed  by  daylight  and  contact,  and  special 
precautions  should  be  taken  against  damp.  The  frame  pads 
should  be  well  dried,  and  a  sheet  of  India  rubber  should  not 
only  cover,  but  overlap  the  platinotype  paper  in  the  frame. 
The  printed  image  is  of  a  peculiar  yellow  orange-  color,  with  a 
tinge  of  green  in  the  deepest  shadows.  When  the  printing  of 
an  average  negative  is  finished,  the  very  highest  lights  are  not 
visible,  and  the  shadows  present  a  color  not  easily  described. 
Practice  is  the  best,  and,  indeed,  the  only  guide  to  correct 
judgment  of  printing.  The  print  should  not  be  too  frequently 
examined,  on  account  of  the  danger  of  both  light-effect  and 
damp.  When  the  printing  is  finished  the  paper  is  placed  in  a 
calcium  tube  as  before. 

Development. — Make  a  saturated  aqueous  solution  at  60  deg. 
Fahr.  of  potassic  oxalate,  rendered  distinctly  acid  with  oxalic 
acid.  (The  Company,  it  appears,  now  recommend  a  faintly 
alkaline  solution.)  Heat  the  solution  to  about  140  deg.  Fahr., 
more  or  less,  according  to  considerations  to  be  pointed  out  pres- 
ently. An  enameled  iron  flat  dish  is  the  article  generally 
used  to  contain  the  solution,  and  a  Bunsen  or  other  burner  is 
placed  below  it  to  keep  the  solution  up  to  temperature  during 
the  process.  The  prints  are  immersed  in  the  solution  for  five 
,  or  six  seconds,  or  they  may  be  pulled  slowly  through  the  solu- 
tion ;  the  image  starts  up  in  black  suddenly.  Air  bells  should 


154  THE    PROCESSES    OF    PURE    PHOTOGRAPHY. 

be  avoided,  but  if  they  occur  the  sheet  must  be  replaced  for  a 
moment  or  two  in  the  solution,  and,  as  a  rule,  no  harm  will  be 
found  to  result  from  the  air  bells  if  this  be  done. 

The  temperature  of  the  bath  is  regulated  chiefly  by  the  amount 
of  printing.  An  over-printed  proof  may  be  developed  in  a 
cooler  solution,  as  120  deg.  Fahr.  An  under-printed  proof  will  be 
saved  by  a  higher  temperature,  as  ISO  deg.  Fahr.  But  the  best 
results  are  got  by  arranging  the  printing  so  that  development 
will  be  performed  at  about  140  deg.  Fahr. 

After  development  the  prints  must  not  be  placed  in  plain 
water,  but  in : 

Water 60  parts 

Hydrochloric  acid 1  part 

If,  on  immersion  of  the  prints,  this  solution  becomes  milky, 
the  acid  is  too  weak.  After  a  few  minutes  in  this  the  prints 
are  removed  to  a  second  bath  of  the  same  constituents,  and 
after  a  few  more  minutes  into  a  third.  The  last  bath  should 
not  show  the  slightest  tinge  of  yellow.  After  the  third  bath 
the  prints  are  to  be  washed  for  about  ten  minutes  in  running 
water,  when  they  will  be  ready  for  drying  and  mounting. 

Sepiatones  on  platinum  prints.  The  Company  sell  paper 
specially  prepared,  and  a  developing  solution  also  prepared  by 
special  methods,  the  nature  of  which  is  not  published,  for  pro- 
ducing a  sepia  tint.  Borlinetto  claims  to  produce  a  sepia  tone 
by  using  a  cold  developer : 

Saturated  solution,  potassic  oxalate,  as  above 40  ounces 

Oxalic  acid 200  grains 

Saturated  solution  of  cupric  chloride,  as  above 4  ounces 

The  prints  may  remain  some  time  in  this  solution,  as  long 
as  twenty  minutes  if  necessary. 

Pizzighelli's  latest  platinotype  experiments.  This  able 
worker  goes  upon  two  leading  principles :  1st.  To  prevent  the 
sensitive  substance  from  sinking  into  the  paper ;  this  he  does 
by  using  a  "  vehicle"  such  as  gum  arabic  or  arrowroot.  2d.  To 
combine  with  the  sensitizer,  from  the  very  first,  a  developing 
solution.  This  he  does  by  adding  to  the  original  potassic 
chloro-platinite  a  quantity  of  neutral  ammonia-ferric  oxalate  or 


THE    PROCESSES    OF    PURE    PHOTOGRAPHY.  155 

sodium-ferric  oxalate.     The  processes  for  preparing  these  ferric 
oxalate  solutions  are  too  intricate  for  us  to  follow  here. 

With  paper  prepared  in  this  manner  we  have  several  alter- 
natives. The  picture  may  be  printed  right  out.  It  may  be 
printed  nearly  out,  and  the  print  left  in  the  dark  to  com- 
plete the  printing,  for  "  the  reduction  of  platinous  chloride, 
once  introduced,  is  continuous  in  the  dark."  Or  the  partly 
printed  out  image  may  be  developed  by 

Saturated  solution  of  sodic  carbonate 5  parts 

Distilled  water  100  parts 

Lastly,  the  paper  may  be  used  exactly  as  ordinary  platino- 
type  paper.  In  all  cases  the  "  clearing  "  is  performed  as  given 
above. 

Any  negative  which  will  give  a  thoroughly  good  print  on 
albumen  paper  will  give  a  good  platinotype  print.  The  quali- 
ties essential  to  the  negative  for  this  process  are  fair  density, 
and  long  scale  of  gradation  from  high-light  to  shadow.  The 
dried  prints  do  not  "  cockle,"  and  the  mounting  needs  no 
special  notice. 


CHAPTER  XXVIII. 
THE  CARBON  PROCESS,  OR  PIGMENT  PRINTING. 

IF  gelatine  is  exposed  to  light  in  presence  of  certain  chro- 
mates,  the  chromate  is  reduced,  chromic  acid  liberated,  and  the 
gelatine  thereby  rendered  insoluble.  If  a  finely-ground  pig- 
ment be  incorporated  with  the  gelatine,  the  pigment  will  re- 
main in  the  insoluble  gelatine  when  the  soluble  is  washed  away, 
and  an  image  consisting  of  pigmented  gelatine  will  be  the 
result.  These  are  the  fundamental  principles  of  the  carbon 
printing  process. 

Carbon  tissue,  as  prepared  for  this  process,  consists  of  paper 
coated  with  gelatine,  containing  in  intimate  mixture  certain 
pigments,  and  containing  also  a  certain  proportion  of  some  such 
substance  as  sugar,  to  prevent  the  dried  tissue  from  being  too 
hard  and  brittle.  The  tissue  is  sometimes  sent  out  sensitized, 
but  it  is  better  for  the  worker  to  sensitize  it  himself,  unless  he 
proposes  to  use  his  sensitized  stock  at  once.  The  unsensitized 
tissue  will  keep  indefinitely. 

The  tissue  is  sensitized  in  a  solution  of  potassic  bichromate, 
rendered  alkaline  with  ammonia.  The  alkali  increases  the 
keeping  qualities  of  the  tissue,  but  perhaps  makes  the  printing 
slower.  A  normal  bath  may  be  : 

Potassic  bichromate 1  ounce 

Water '. 30  ounces 

Ammonia,  at  least 1  dram 

but  not  more  than  will  change  the  reddish  color  of  the  bichro- 
mate solution  to  yellow. 

In  very  hot  weather  and  for  very  thin  negatives  the  propor- 
tion of  water  may  be  greatly  increased  (say  to  50  ounces  for  1 
ounce  of  bichromate),  and  for  very  hard  negatives  the  solution 
may  be  more  concentrated  (as  7  ounces  of  water  to  1  ounce 


THE    PROCESSES    OF    PUKE    PHOTOGRAPHY.  157 

bichromate.)  In  very  hot  weather  as  much  as  30  per  cent,  of 
the  water  may  be  replaced  by  alcohol. 

Apparatus  required  for  sensitizing  :  A  flat  dish  of  porce- 
lain, glass,  zinc  or  papier  mache,  a  sheet  of  glass  larger  than 
the  sheet  to  be  sensitized,  and  a  squeegee.  The  solution  to  be 
about  an  inch  deep  in  the  dish,  and  the  tissue  to  be  immersed 
in  the  solution.  If  air  bells  form  they  are  to  be  brushed 
away  at  once.  The  solution  should  be  of  moderate  temperature, 
not  over  60  deg.  Fahr.;  the  colder  the  solution  the  longer  the 
time  of  immersion,  four  or  five  minutes  may  be  taken  as  an 
average  time.  After  this  time  the  tissue  is  laid  face  down  on 
the  glass  plate,  and  the  back  squeegeed  to  remove  surface  mois- 
ture. The  tissue  is  then  removed  from  the  glass,  and  dried  in 
the  form  of  a  bow,  face  outward  and  upward,  in  a  place  ab- 
solutely free  from  noxious  fumes,  as  of  combustion  of  gas. 
The  tissue  is  "  insensitive  "  while  wet,  but  is  better  dried  in 
non-actinic  light.  When  a  brown  discoloration  is  seen  in  the 
sensitizing  solution  it  should  be  rejected. 

Tissue,  immediately  after  it  is  dry,  prints  somewhat  slowly 
with  strong  contrast.  As  the  tissue  is  kept  after  sensitizing  it 
prints  more  and  more  quickly,  giving  even  increasing  "  soft- 
ness "  till  at  last  it  passes  into  a  state  of  fog  and  insolubility.  If 
the  tissue  be  kept  dry  it  ought  to  remain  workable  for  seven 
or  ten  days  after  being  sensitized,  and  a  large  proportion  of 
ammonia  in  the  sensitizing  bath  conduces  to  this  quality  of 
keeping. 

Mr.  H.  J.  Burton  has  suggested  an  excellent  method  of  sen- 
sitizing carbon  tissue.  He  lays  the  tissue  flat  on  clean  blotting 
paper  and  sponges  on  to  the  back  a  very  strong  sensitizing  solu- 
tion. 

Potassic  Bichromate 4  ounces 

Liq.  Amm.  fort 1  ounce 

Water  20  ounces. 

Mix  the  ammonia  and  the  water,  grind  up  the  bichromate  and 
dissolve  in  the  mixture.  The  tissue  by  this  process  may  be 
used  much  sooner,  in  hotter  weather  without  fear  of  solution 
of  the  gelatine,  and  the  face  of  the  tissue  is  kept  cleaner. 


158  THE    PROCESSES    OF    PUKE    PHOTOGRAPHY. 

Before  printing,  a  "  safe  edge"  must  be  put  round  the  negar 
tive,  or,  more  accurately,  round  the  edges  of  the  sheet  of  tissue, 
though  the  safe  edge  is  usually  attached  to  the  negative. 
Black  varnish  may  be  painted  round  the  edges  of  the  negative 
with  a  brush  tied  along  a  slip  of  wood,  the  wood  acting  as 
a  guide  along  the  edges  of  the  negative  ;  or  a  mask  or  yellow 
paper  may  be  used,  absolute  opacity  of  the  safe  edge  is  not  de- 
sirable. If  the  safe  edge  is  omitted  and  the  extremities  of  the 
tissue  left  unprotected,  mischief  will  surely  happen  later. 

The  progress  of  printing  cannot  be  gauged  in  the  usual  way, 
for  no  visible  image  is  produced  by  light  alone.  We  have  there- 
fore to  judge  the  time  necessary  by  comparison  with  some  sen- 
sitive substance  yielding  a  visible  image  by  light  action.  Sen- 
sitized albumen  paper  is  commonly  used  in  an  "  actinometer." 
An  actinometer  containing  a  piece  of  sensitized  albumenized 
paper  is  exposed  to  the  light  along  with  and  beside  the  carbon 
tissue,  and  a  proportion  between  the  sensitiveness  of  the  albu- 
men paper  and  the  tissue  being  established,  nothing  remains 
but  to  make  allowance  for  the  quality  of  the  negative  being 
printed  on  the  tissue. 

There  are  two  types  of  actinometer,  in  one  the  sensitive 
paper  is  exposed  uncovered  to  light,  and  close  to  the  sensitive 
paper  is  a  painted  standard  color  similar  to  the  color  taken  by  a 
piece  of  sensitized  albumen  paper  on  exposure  to  light.  When 
the  exposed  paper  takes  the  color  represented  ~by  the  paint 
"  one  tint"  is  registered,  a  fresh  white  piece  of  paper  exposed 
for  the  "  second  tint,"  and  so  on.  This  actinometer  requires 
pretty  constant  watching.  The  other  type  consists  of  a  small 
printing  frame  in  which  the  sensitized  paper  is  covered  with  a 
scale  of  squares  of  varying  opacity.  No.  I  square  being  the 
least  opaque.  The  "  Warnerke  Sensitometer  Screen  "  is  an  il- 
lustration of  this  principle.  In  this  case  the  sensitive  paper  is 
exposed  beneath  the  whole  scale,  and  one  figure  becomes  legible 
after  the  other ;  when,  for  instance,  No.  4  is  legible  "  4  tints  "  are 
said  to  be  registered.  As  both  of  these  sensitometers  or  actino- 
meters  are  exposed  alongside  of  the  carbon  tissue,  it  is  evident 
that  when  once  the  proper  exposure  for  any  negative  has  been 
determined  with  either  of  these  instruments,  the  same  number 


THE    PROCESSES    OF    PURE    PHOTOGRAPHY.  159 

of  tints  will  always  prove  right  for  that  negative,  time  and 
quality  of  light  being  per  se  matters  of  indifference.  The 
proper  number  of  "  tints  "  for  each  negative,  being  once  founcl. 
should  be  marked  on  the  negative  to  save  future  trouble, 
Practised  carbon  printers  can  judge  of  the  exposure  necessary 
for  each  negative  without  using  actinometers.  Any  number 
of  negatives  whose 'required  "  tints"  are  known  can  be  printed 
at  one  time,  provided  that  an  actinometeris  exposed  at  the  same 
time  as  the  tissue,  for  when  the  actinometer  marks  (say)  "  3 
tints  "  all  the  negatives  marked  "  3  "  are  removed  from  the 
printing  light.  Carbon  tissue  prints  on  an  average  from  50  to 
25  percent,  more  quickly  than  albumenized  paper. 

If  a  carbon  print  after  exposure  be  kept  in  the  dark  for  a 
time,  the  effect  on  the  print  is  the  same  as  if  a  longer  exposure 
had  been  given.  This  action  has  been  called  the  "  continuat- 
ing  action,"  and  is  directly  proportionate  to  the  amount  of 
moisture  reaching  or  present  in  the  tissue.  To  some  authori- 
ties it  is  a  question  whether  this  continuating  action  is  not 
identical  with  the  stages  of  insolubility  reached  by  tissue  never 
exposed  to  light.  As  the  quantity  of  moisture  in  the  air  is 
constantly  varying,  it  would  be  next  to  impossible  to  judge  of 
the  time  for  which  a  print  might  be  kept  after  exposure,  but 
luckily,  in  development  we  have  ample  power  to  correct  any 
slight  error  in  judgment  as  to  exposure.  Some  authorities 
assert  that  tissue  prints  best  perfectly  dry ;  others  prefer  a 
slightly  damp  state.  Testing  these  opinions,  we  found  it  im- 
possible to  judge  between  them,  except  that  we  noticed  the 
effect  of  continuating  action  in  the  damp  tissue ;  and  it  must 
be  noted  that  this  action  begins  with  the  exposure  of  the  tissue. 

Development  consists  simply  of  solution  of  the  gelatine  not 
affected  by  light,  and  hot  water  is  the  solvent ;  but  certain 
considerations  must  not  be  overlooked.  As  the  pigment  is 
very  dark,  and  the  film  pretty  thick,  it  is  certain  that  the  part 
of  the  film  next  the  paper  is  quite  soluble,  not  having  been  acted 
upon  by  light.  Therefore  we  have  to  dissolve  the  lower 
stratum  of  gelatine  and  remove  the  paper  from  the  back.  To 
do  this  we  have  to  attach  the  tissue  by  its  face  to  a  support, 
rigid  or  flexible,  and  when  the  paper  backing  is  removed  we 


160  THE    PROCESSES    OF    PUKE    PHOTOGRAPHY. 

have  evidently  a  "  reversed  "  picture.  This  fact  entails  the 
operation  known  as  "  double  transfer,"  unless  in  the  first  in- 
stance the  negative  was  "  reversed." 

We  shall  begin  by  outlining  the  process  of  producing  a  posi- 
tive by  "  single  transfer,"  using,  suppositiously,  an  opal  plate 
for  the  final  support  of  the  picture.  The  apparatus  required 
will  be  a  dish  as  before,  a  squeegee,  and  a  plate  of  opal.  The 
opal  is  laid  in  the  dish  and  covered  with  cold  water  to  the 
depth  of  about  two  inches  ;  the  exposed  sheet  of  tissue  is  im- 
mersed in  the  water.  At  first  the  tissue  will  curl  up,  but  after 
a  short  time  will  uncurl  and  lie  flat.  As  soon  as  it  is  flat  it  is 
brought  face  to  face  with  the  opal,  and  the  two  raised  together 
from  the  water  and  laid  down  or  a  table,  tissue  uppermost.  A 
piece  of  rubber  or  American  cloth  is  laid  on  the  tissue,  the 
squeegee  applied,  the  cloth  removed,  and  a  piece  of  blotting- 
paper  put  in  place  of  the  cloth  ;  a  flat  board  is  laid  on  the  top, 
and  a  weight  on  the  board.  If  several  sheets  of  tissue  are  to 
be  developed,  they  go  through  this  process  one  after  another 
till  all  are  piled  one  over  the  other,  and  the  board  and  wreight 
over  all.  Development  must  not  be  attempted  with  any  tissue 
till  it  has  been  at  least  ten  minutes  under  the  weight — fifteen 
minutes  will  be  safer.  The  dish  is  now  filled  with  water  at 
about  100  deg.  Fahr.,  and  the  plates  bearing  the  tissue  put  in 
altogether,  or  one  by  one.  Baths  are  made  with  grooves,  so 
that  several  plates  can  be  developed  at  once.  Presently  the 
colored  pigment  will  be  seen  to  ooze  out  at  the  edge  of  the 
paper,  if  a  "  safe  edge  "  was  not  omitted,  and  a  short  time  later 
the  paper  will  leave  the  plate  at  the  corners.  The  paper  may 
be  then  removed  carefully  with  the  hand.  After  this  the  plate 
is  bathed  with  hot  water  till  the  mass  of  dirty  black  pigment  is 
entirely  removed  from  all  but  the  image,  a  transformation  both 
surprising,  to  the  beginner,  and  pleasant.  It  is  not  advisable  to 
raise  the  temperature  of  the  water  much  above  100  or  110 
deg.  Fahr. 

Under-exposure  will  show  itself  in  over-solubility  of  the 
gelatine  ;  the  half-tones  of  the  image  will  be  washed  right  away 
and  even  the  shadows  will  suffer.  If  anything  at  all  can  save 
an  under-exposed  print,  reduction  of  the  temperature  to  about 


THE  PROCESSES  OF  PURE  PHOTOGRAPHY.         161 

80  deg.  will  save  it,  but  tlie  better  plan  is  to  try  again,  giving 
more  exposure  a  "  tint "  or  two  more. 

Over-exposure  will  show  itself  by  insolubility  of  the  gelatine ; 
the  high-lights  will  persistently  retain  a  dirty  color,  the  shad- 
ows will  appear  simply  a  black  mass.  If  prolonged  develop- 
ment and  persevering  laving  on  of  the  water  fail  to  complete 
the  development,  the -temperature  of  the  water  may  be  raised 
till  uncomfortable  to  the  hand.  Failing  this,  ammonia  may  be 
added  to  the  water  as  a  last  resource ;  but  the  best  plan  is  to 
make  another  exposure  of  several  "  tints  "  less,  or  to  keep  the 
tissue  a  shorter  time  after  exposure. 

"When  development  is  complete  and  the  picture  appears  as 
is  required,  the  image-bearing  plate  is  washed  in  cold  water, 
soaked  in  a  four  per  cent,  solution  of  potash  alum,  washed 
again,  and  dried.  We  have  now  produced  a  print  by  the  single 
transfer  process;  it  is  on  opal  glass,  and  probably  reversed; 
but  instead  of  opal  we  might  have  used  a  glass  plate  or  a  piece 
of  prepared  paper,  and  in  place  of  an  ordinary  negative  we 
might  have  used  one  originally  "  reversed "  by  means  of  a 
prism,  or  reversal  of  the  plate  in  the  dark-slide. 

But  supposing  our  aim  is  to  get  a  non-reversed  print  from 
an  ordinary  negative,  all  we  have  to  do  is  to  attach  to  our 
reversed  jfositive  a  piece  of  paper  and  detach  the  positive  in 
adhesion  to  the  paper  from  the  opal.  This  would  be  a  "  double 
transfer"  process. 

The  double  transfer  process  may  be  said  to  consist  in  trans- 
ferring the  image  first  to  a  temporary  support,  whereon  it  is 
developed,  thereafter  to  its  permanent  support. 

As  temporary  support  we  may  use  a  prepared  paper  sold 
under  the  name  of  "  flexible  support,"  being  coated  with  some 
highly  polished  and  impervious  substance  which  is  waxed. 
The  following  will  answer  for  the  waxing  solution  : 

Yellow  resin 5  drams 

Beeswax 3  drams 

Turpentine 1  pint 

(The  paper,  when  first  used,  does  not,  as  a  rule,  need  to  be 
waxed,  as  it  is  sold  (by  the  Autotype  Co.,  at  least)  ready  for 
use.  But  if  it  is  to  be  used  over  again  it  must  be  re-waxed.) 


162  THE    PROCESSES    OF    PDBE    PHOTOGRAPHY. 

If  a  high  gloss  is  required  on  the  finished  print,  a  plate  of 
glass  must  be  cleaned,  rubbed  with  French  chalk  (or  talc),  col- 
lodionized,  washed,  etc.,  as  on  page  106. 

A  grained  surface  is  obtained  by  using,  as  temporary  sup- 
port, a  sheet  of  grained  zinc,  waxed  as  above.  In  any  case, 
the  first  transfer  is  made  exactly  as  already  described,  opera- 
tions being  the  same  up  to  the  washing  after  alum ;  the  washed 
film  is  not  dried,  but  is  brought  into  contact  with  a  sheet  of 
so-called  "double  transfer  paper,"  or  "permanent  support." 
This  is  paper  coated  with  gelatine  and  barium  sulphate,  to 
which  alum  is  sometimes  added.  It  is  better,  however,  to  omit 
the  alum,  as  the  Autotype  Co.  now  do,  and  to  bathe  the  un- 
alumed  paper  in : 

Potash  alum %  of  an  ounce 

Water 1  pint 

A  piece  of  permanent  support  for  each  print  is  immersed 
in  this  about  the  same  time  as  the  development  of  the  print 
begins.  This  support  is  squeegeed  in  the  usual  way  to  the 
developed  image,  and  the  whole  is  allowed  to  dry,  after  which 
a  knife  point  is  inserted  under  one  corner  of  the  print  and  the 
print  will  readily  leave  the  temporary  support,*  which,  if 
"  flexible  support,"  needs  only  re-waxing  to  be  ready  for  use- 
again.  For  obtaining  the  highest  gloss  a  sheet  of  opal,  collo- 
dionized  as  above,  may  be  used,  this  enables  the  progress  of 
development  to  be  well  watched. 

To  make  lantern-slides  by  the  single  transfer  carbon  process, 
a  tissue  containing  a  large  amount  of  coloring  matter  should 
be  used  ;  such  a  tissue  is  prepared  by  the  Autotype  Co.  for 
the  purpose.  The  glass  used  as  support  should  be  coated 
with  the  following  and  dried  in  full  daylight. 

Gelatine 1  ounce 

Potassic  bichromate 2  drams 

Water 20  ounces 

The  rest  of  the  process  differs  in  no  way  from  ordinary 
single  transfer. 


THE  PROCESSES  OF  PUKE  PHOTOGRAPHY.  163 

DEFECTS  AND  REMEDIES. 

Insolubility  of  tissue,  due  to  drying  in  warm  damp  air. 
Acid  sensitizing  bath.  Too  long  keeping  after  sensitizing. 
Bichromate  bath  decomposed.  Actinic  light  and  "  continua- 
tive  action." 

The  tissue  melts  in  the  sensitizing  bath.  Too  high  tem- 
perature. Ice  the  solution  or  replace  twenty-five  per  cent, 
of  the  water  with  alcohol. 

The  tissue  becomes  hard  or  cracJdy.  Air  too  dry.  Keep 
in  a  damp  place  or  add  a  very  little  glycerine  to  sensitizer. 

The  prints  refuse  to  adhere  to  temporary  support  before 
development.  If  at  edges  only,  want  of  "  safe  edge."  If  all 
over,  tissue  insoluble.  Or  the  tissue  allowed  to  remain  too 
long  in  the  plain  water  before  squeegeeing  to  temporary  sup- 
port. As  the  swelling  of  the  gelatine  causes  the  adhesion,  it 
is  evident  that  if  the  swelling  is  complete  before  squeegeeing 
no  adhesion  can  result.  Insufficient  time  allowed  under  the 
weight. 

Spots. — Perhaps  due  to  air  bells  between  tissue  and  support. 
Air  bells  are  very  apt  to  form  in  the  cold  water  bath ;  they 
must  be  watched  for  and  removed. 

Reticulation,  or  an  appearance  of  "  grain "  in  the  image, 
A  mysterious  and  not  uncommon  defect,  due  probably  to  in- 
cipient insolubility.  Remedy :  Observe  all  the  •precautions 
suggested  for  cases  where  the  tissue  refuses  to  adhere  to  tem- 
porary support. 

The  prints  with  their  final  support  refuse  to  leave  the  tem- 
porary support.  Imperfect  waxing  or  talcing. 


CHAPTER  XXIX.       . 
POSITIVES  AND  NEGATIVES  BY  ENLARGEMENT. 

THE  optics  of  enlargement  may,  in  principles,  be  classified 
under  two  heads :  1st.  The  optical  principles  of  illuminating 
the  original.  2d.  The  optical  principles  of  projecting  the 
image  to  form  the  enlargement. 

Under  the  first  heading  we  have  various  processes  depending 
upon  the  radiant,  its  nature  and  its  position  :  if  the  source  of 
light  be  infinitely  distant,  practically  speaking,  as  the  sun ;  or 
if  it  be  practically  at  a  point  somewhere  near  the  negative,  as 
a  lamp  or  electric  arc ;  in  other  words,  if  the  rays  be  parallel 
to  each  other  or  divergent,  then  we  use  a  condenser  to  "  con- 
dense "  or  collect  rays  that  would  otherwise  pass  outside  of  the 
objective  or  projecting  lens.  This  condenser  is  a  lens,  or  com- 
bination of  lenses,  at  least  as  large  in  area  as  the  negative  (or 
positive)  to  be  enlarged  from,  and  it  acts  by  collecting  the  rays, 
passing  them  all  through  the  negative  (or  positive)  and  bringing 
them  to  a  focus  inside  the  projecting  lens.  Naturally,  there- 
fore, where  an  originally  powerful  light  is  used  (as  the  direct 
rays  of  the  sun),  the  light  projected  through  the  projecting  lens 
is  extremely  powerful,  and  this  process  of  solar  enlargement  is 
well  suited  for  enlarging  upon  surfaces  of  low  sensitiveness,  as 
carbon  tissue  or  albumen  paper  ;  and  it  is  equally  evident  that 
where  we  have  to  use  a  light  of  but  little  actinic  power,  as  a 
lamp  light,  a  condenser  enables  us  to  succeed  with  an  exposure 
which,  even  on  a  moderately  sensitive  surface,  as  bromide 
paper,  would  otherwise  be  totally  inadequate  to  produce  any 
developable  image  at  all,  not  to  mention  an  image  on  any 
printing-out  material.  Enlargement  by  the  solar  camera  is 
now  so  little  used  by  any  but  great  firms  requiring  it  for 
special  purposes,  and  with  the  sensitiveness  of  the  films  at  our 


THE    PROCESSES    OF   PURE   PHOTOGRAPHY. 


165 


service  it  is  so  little  necessary,  that  it  is  not  proposed  to  go 
into  this  subject  here  at  all.  Enlargement  with  a  condenser  in 
an  optical  lantern  will  be  noticed  presently.  All  that  requires 
to  be  said  here  is  that  the  diameter  of  the  condenser  must  be  at 
least  equal  to,  and  should  be  greater  than,  the  diagonal  of  the 
original  plate  or  part  of  the  plate  -to  be  enlarged,  and  that  the 
front  focus  of  the  condenser  should  fall  within  the  projecting 
lens.  To  illustrate  this  we  give  a  diagram,  Fig.  25.  Here  A 


FIG.  25. 

is  the  radiant ;  B,  the  condenser ;  (7,  the  negative  held  in  a 
frame  E ' ;  D  is  the  objective  or  projecting  lens,  in  this  case  a 
photographic  lens.  To  get  the  greatest  benefit  from  B  the 
relative  distances  of  A  B  and  D  must  be  such  that  the  focus 
of  B  falls  within  D.  The  larger  the  condenser  the  more  light 
it  will  collect  and  concentrate,  so  the  exposure  varies  inversely 
as  the  area  of  the  condenser.* 

Enlarging  without  a  condenser  by  reflected  or  diffused  light. 
— When  daylight  is  used  with  such  a  printing  surface  as  brom- 
ide paper  or  wet  collodion,  the  exposure  required  is  not  un- 
reasonably long ;  and  this  system  will  probably  commend  itself 
as,  on  the  whole,  the  most  simple  and  satisfactory  process  for 
obtaining  either  an  enlarged  negative  for  contact  printing,  or 
a  direct  positive  enlargement.  If  the  original  is  a  negative  we 
can  only  produce  a  direct  positive ;  but  if  we  have  previously 
produced  a  positive  from  our  original  negative,  and  enlarge 
that  positive,  we  shall  get  an  enlarged  negative,  which  can  be 
printed  by  contact  in  the  usual  way.  A  positive  made  for  the 
latter  purpose  should  be  full  of  detail  and  almost  what  might 
be  called  slightly  fogged  in  the  high  lights.  A  positive 

*  It  will  be  noticed  that  the  condenser  in  this  cut  is  capable  of  illumi- 
nating a  larger  negative  than  C. 


16(5 


THE    PROCESSES    OF    PURE    PHOTOGRAPHY. 


resembling  a  good  lantern-slide  is  not  so  suitable  for  this  pur- 
pose as  one  resembling  many  of  the  lantern-slides  often  seen 
exhibited. 


FIG.  26. 

We  here  figure  an  arrangement  for  daylight  enlarging,  so 
simple  that  any  intelligent  reader  will  understand  it,  and  so 
easily  made  that  with  the  help  of  a  carpenter  anyone  can 
construct  a  similar  one  in  a  few  hours,  except,  perhaps,  the 
camera,  which,  however,  may  be  of  the  simplest  construction. 

The  cut  (  Fig.  26)  is  taken  from  the  "  Practical  Guide  to 
Photographic  and  Photo  Mechanical  Printing  Processes,"  by 
one  of  the  writers,  and  we  are  indebted  to  Messrs.  Marion  & 
Co.  for  the  block.  The  design,  though  exceedingly  simple, 
suffices  to  show  the  general  arrangement  of  parts ;  greater  ele- 
gance and  convenience  may  be  obtained  by  the  addition  of  sev- 
eral movements,  sufficiently  evident.  The  negative  to  be  en- 
larged from  is  placed  in  the  back  of  the  camera  <7,  which  is 
fixed  to  an  aperture  in  a  wall  preferably  facing  the  north,  D  is 
a  long  base-board,  along  which  slides  the  easel  E,  to  which  is 
pinned  the  sensitive  material,  if  paper,  or  on  which  is  fixed,  in 
any  suitable  way,  the  sensitive  surface  if  glass.  The  easel  E 
may  have  its  centre  cut  out,  and  a  piece  of  ground-glass  may 
be  fixed  in  a  rebate,  and  the  focusing  done  from  behind,  J^is 
a  reflector,  and  may  be  a  board  covered  with  some  matt  white 
substance,  as  blotting  paper,  but  shiny  papers  should  be  avoided. 
F  should  be  considerably  larger  than  the  plate  being  enlarged 
from,  and  F\&  to  be  so  arranged  that  the  plate  view  from  in- 
side is  evenly  illuminated  all  over. 


THE   PROCESSES   OF    PUKE    PHOTOGRAPHY.  lf)7 

As  to  the  lens  used  for  projection,  though  any  lens,  how- 
ever short  its  focus,  may  be  used  with  a  condenser,  the  same 
does  not  hold  good  with  a  reflector.  In  the  latter  case  the  lens 
should  be  of  sufficient  focus,  at  least,  to  have  produced  the 
original  negative  at  full  aperture.  A  half-plate  negative  can- 
not in  this  way  be  enlarged  with  a  4-inch  lens  ;  and  even  if  a 
7^-inch  lens  be  used,  it  will  probably  require  a  stop  to  make  it 
cover  sharp  to  the  edges.  But  if  the  focus  of  the  projection 
lens  be  ample,  no  stop  will  be  required  at  all,  as  we  have  to 
deal  with  parallel  surfaces. 

If  a  scale  of  inches  be  marked  on  the  baseboard  of  the 
camera,  and  also  on  the  long  board,  Z>,  or  on  the  floor  in  the 
case  of  a  separate  easel,  and  if  the  table  of  enlargements  found 
at  the  end  of  this  book  be  consulted,  the  relative  positions  of 
the  various  parts  can  be  very  easily  regulated,  and  the  focus 
almost  precisely  found  without  examination.  Suppose,  for 
instance,  it  is  desired  to  enlarge  a  quarter-plate  negative  to  a 
whole-plate  positive,  with  a  lens  of  6  inches  focus.  Consult- 
ing the  table,  we  find  in  the  proper  square  under  "  4  times  "  73°. 
"We,  therefore,  at  once  place  the  centre  of  our  lens  7£  inches 
from  the  negative,  and  our  easel  30  inches  from  the  lens.  We 
then  arrange  our  picture  suitably  on  a  piece  of  plain  white 
paper  attached  to  the  easel,  raising  or  lowering  our  camera 
front  or  our  easel  as  desired. 

An  even  less  cos'tly  arrangement  for  enlarging  verjr  small 
negatives,  as  quarter-plates,  to  moderate  sizes,  as  10x12  (pro- 
vided the  worker  has  two  cameras,  a  small  one  and  a  large  one, 
with  sufficient  stretch),  is  figured  27  on  page  173.  For  enlarg- 
ing, of  course,  this  arrangement  is  reversed — that  is  to  say,  the 
small  camera  is  placed  next  the  light.  With  this  arrangement 
good  enlargements  may  be  produced  without  any  specially 
adapted  apartment. 

It  is  impossible  to  lay  lown  rules  for  exposure,  so  many 
different  cases  have  to  be  met.  The  light  varies,  our  sensi- 
tive materials  vary,  our  negatives  vary  ;  but  supposing 
there  was  no  variation  in  these,  and  supposing  the  same 
lens  with  the  same  aperture  to  be  invariably  used,  we 
can  then  give  at  least  one  rule  which  will  be  of  service. 


168  THE    PROCESSES    OF   PURE    PHOTOGRAPHY. 

Exposure  varies  directly  as  "times"  of  enlargement.  Example : 
To  enlarge  a  quarter-plate  negative  to  whole  plate  (4  areas) 
the  required  exposure  is  found  to  be  ten  minutes.  To  enlarge 
the  same  negative  under  the  same  conditions  of  light,  lens, 
sensitive  surface,  etc.,  to  13x17  inches  (16  areas),  the  ex- 
posure required  would  be  forty  minutes :  4 : 16  : :  10 : 40. 

During  exposure  no  actinic  light  must  enter  the  apartment, 
and  during  focusing  it  is  well  to  allow  no  light  to  enter 
the  room  at  all,  actinic  or  otherwise,  except  what  passes 
through  the  negative  and  the  projection  lens.  While  the  sensi- 
tive material  is  being  put  in  position  after  focusing,  the  lens  is 
to  be  capped,  and  the  room  may  be  illuminated  by  non-actinic 
light,  for  which  provision  was  made.  While  the  exposure  is 
going  on  a  great  deal  can  be  done  in  the  way  of  "  dodging." 
Vignettes  of  any  shape  can  be  produced  by  cutting  an  aperture 
of  the  required  shape  in  a  piece  of  cardboard  or  wood,  and 
holding  the  mask  so  made  between  the  lens  and  the  sensitive 
surface,  moving  the  mask  constantly  to  and  from  the  sensitive 
material.  As  the  image  is  plainly  seen  projected  on  the  sensi- 
tive surface,  this  operation  is  one  of  perfect  simplicity.  In  like 
manner  any  part  of  the  image  that  prints  too  dark  can  be 
shaded  during  part  of  the  exposure.  But  in  any  case  the  mask 
should  be  kept  on  the  move,  else  hard  lines  will  result  on  the 
print. 

Whatever  be  the  sensitive  surface  used,  bromide  paper,  wet 
collodion,  etc.,  development  is  conducted  as  already  laid  down 
under  the  several  headings.  When  large  sheets  of  paper  are 
used  special  developing  dishes  may  be  required ;  dishes  for 
larger  sheets  may  be  made  with  plate  glass  bottoms  and  var- 
nished wooden  sides. 

Enlarging  by  the  Optical  Lantern  with  (1)  an  oil  lamp  (2) 
oxyhydrogen  lime  light.  This  is  perhaps  the  favorite  process 
with  amateurs,  and  it  is  certainly  a  convenient  and  simple 
process  for  enlarging  small  originals.  But  the  condenser 
must  be  of  diameter  equal  to,  and  ought  to  be  of  diameter 
slightly  greater,  than  the  diagonal  of  the  part  to  be  enlarged. 
In  the  next  place  the  lantern  nozzle  should  be  so  constructed 
as  to  allow  the  objective  to  be  racked  to  at  least  twice  its  own 


THE   PROCESSES    OF    PUKE    PHOTOGRAPHY.  169 

focal  length  from  the  negative.  The  sensitive  material  is  fixed 
in  front  of  the  objective,  which  may  be  a  portrait  lens,  and  the 
whole  system  from  light  to  sensitive  material  should  be  axially 
centered,  and  the  paper  or  glass  parallel  with  the  negative. 
No  light  must  stray  from  the  lantern  so  as  to  affect  the  sensi- 
tive material,  so  it  is  usual  to  inclose  the  ordinary  optical  lan- 
tern in  a  larger  box,  the  nozzle  only  protruding  thro  ugh  a  hole 
for  the  purpose.  Lanterns  are,  however,  made  specially  for 
the  purpose  of  enlarging,  and  usually  are  well  adapted  for  that 
purpose. 

When  the  oxyhydrogen  light  is  used  the  area  of  incandes- 
cence of  the  lime,  being  but  small,  is  easily  placed  in  the  focus 
of  the  condenser,  but  where  a  lamp  with  several  wicks  is  used 
there  is  apt  to  be  a  considerable  loss  of  light.  To  obviate  this 
loss  of  light  Mr.  J.  Traill  Taylor  suggests  the  use  of  a  simple 
supplementary  lens  placed  between  the  light  and  the  conden- 
ser, and,  like  most  of  that  gentleman's  optical  suggestions,  this 
one  is  very  valuable. 

The  same  rules  hold  good  for  this  process  of  enlarging,  with 
regard  to  exposure,  as  for  the  daylight  process.  The  effect  of 
the  condenser  in  shortening  the  exposure  may  seem  astonish- 
ing to  the  beginner,  who  is  ignorant  of  the  optics  of  the  mat- 
ter. Vignetting  and  other  "  dodging  "  are  quite  as  easy  with 
artificial  light  as  daylight. 

We  have  seen  and  used  an  arrangement  for  enlarging  still 
more  simple  and  less  costly  than  'those  described  above.  No 
condenser  was  used,  but  the  artificial  light  was  diffused  over  the 
original  by  means  of  a  sheet  of  finely  ground-glass  placed  be- 
tween the  light  and  the  negati  ve,and  about  one  and  one-half  inch 
behind  the  original.  By  this  process  a  much  larger  negative 
may  be  enlarged  by  artificial  light,  but  the  exposure  is  very 
long,  and  the  rules  for  choice  of  projection  lens  are  the  same  as 
for  daylight  enlarging  with  a  reflector,  that  is  to  say  the  pro- 
jecting lens  must  be  of  long  focus.  If  the  original  be  un- 
usually large,  as  8x10  or  10x12  inches,  several  lights  will  be  re- 
quired to  illuminate  the  original  evenly,  the  only  alternative — 
removing  the  light  to  a  considerable  distance  from  the  ground- 
glass — entailing  an  inconvenient  duration  of  exposure. 


170 


THE    PROCESSES    OF   PUKE    PHOTOGRAPHY. 


Collodion  Transfers  are  produced  by  coating  a  talced  sheet 
of  glass  with  iodized  collodion,  sensitizing,  developing,  fixing 
and  washing  in  the  usual  way,  provision  being  made  for  secur- 
ing pleasing  tones.  The  film  is  then  placed  in  contact  with  a 
sheet  of  paper  such  as  "  Carbon  Double  Transfer  "  (see  page 
162),  squeegeeing  the  paper  to  the  film,  drying,  and  stripping 
from'  the  glass.  These  transfers  are  usually  enlargements, 
which  is  our  reason  for  mentioning  them  here. 


CHAPTEE  XXX. 
LANTERN    SLIDES. 

PHOTOGRAPHY,  perhaps,  reaches  its  climax  of  beauty  and 
utility  in  a  good  lantern-slide  shown  on  a  good  screen  with  a 
good  light.  The  size  of  the  view  so  shown  is  not  per  se  the 
chief  advantage,  but  it  enables  a  number  of  people  to  see  in 
company  which  is  always  pleasing  to  the  majority  of  people. 
The  optical  lantern  is  valuable  both  to  art  and  science,  for 
while  pictures  may  be  shown  on  a  scale  more  dignified  and 
more  worthy  of  their  merits,  scientific  facts  may  be  demon- 
strated in  a  manner  precluding  mistake,  and  with  a  weight 
of  evidence  precluding  unbelief.  But  while  a  good  lantern- 
slide  is  a  thing  of  beauty  and  of  utility,  a  bad  one  is  a  horror 
which  we  too  often  see  in  public  exhibitions,  not  to  mention 
private  ones. 

The  worker  must  first  learn  the  characteristics  of  a  good 
slide,  and  they  are  not  learned  without  considerable  study. 
A  slide  may  be  a  very  pretty,  little,  positive  transparency,  and 
yet  totally  useless  as  a  lantern-slide.  A  slide  must  have,  first, 
absolute  clearness  in  the  highest  lights ;  second,  transparent 
shadows.  If  either  of  these  points  is  transgressed  the  slide  is 
useless,  to  start  with.  But  besides  the  highest  lights  no  other 
part  must  be  absolutely  clear.  The  midsummer  snow  scenes, 
so  frequently  seen — and  frequently  applauded  by  an  ignorant 
public — are  the  results  of  neglect  of  this  rule.  These  "  hard  " 
slides  are  usually  the  result  of  either  hard  negatives  or  under- 
exposure of  the  slides,  necessitating  forced  development.  A 
slide  must  have  plenty  of  half  tone,  but  not  too  much.  The 
commonest  type,  perhaps,  of  bad  slides,  is  that  where  we  see 
nothing  but  half  tone,  to  put  it  mildly,  or  nothing  but  incipi- 
ent fog,  to  put  it  plainly.  Beginners  with  gelatine  bromide 


172  THE   PROCESSES    OF   PURE   PHOTOGRAPHY. 

for  lantern-slides  are  very  apt  to  produce  these  foggy  lides ; 
nothing  can  be  uglier,  unless  it  is  the  snow  scenes  already 
alluded  to.  A  slide  must  have  : 

1.  Clear  highest  lights. 

2.  Half-tone  in  secondary  lights. 

3.  Detail  in  the  shadows. 

-4.  A  pleasing  "  tone  "  or  color. 

The  processes  commonly  used  for  producing  lantern- slides 
are :  Wet  collodion,  dry  collodion,  gelatine  chloride,  gelatine 
bromide.  In  point  of  exposure  the  gelatine  bromide  is  by  far 
the  quickest  of  these  processes,  gelatine  chloride  is  so  insensi- 
tive that  practically  it  is  only  used  for  making  "  slides  by  con- 
tact." When  the  negative  is  just  about  the  size  required  for 
a  lantern-slide  (three  and  a  quarter  inches  square),  contact 
printing  is  resorted  to,  a  sensitive  plate  taking  the  place  of  a 
piece  of  paper  used  for  ordinary  printing  in  a  frame ;  care 
must  be  taken  not  to  scratch  the  negative  nor  the  sensitive 
plate  when  bringing  the  two  together.  When  the  negative 
is  larger  than  the  standard  slide  size,  the  slide  has  to  be  made 
by  "  redaction  in  the  camera."  The  process  of  reduction  is 
simply  making  a  copy  on  glass  of  the  negative  by  transmitted 
light  ;  the  copy  will,  of  course,  be  a  positive. 

Mechanical  Arrangements  for  Reducing. — As  a  matter  of 
practice  any  means  whereby  a  copy  may  be  made  of  the  nega- 
tive as  above,  the  copy  being  of  the  proper  size,  will  answer 
for  making  a  slide  by  reduction,  but  it  is  found  better  to  take 
precautions  to  prevent  any  light,  other  than  what  passes  through 
the  negative,  from  reaching  the  copying  lens.  Many  costly 
and  intricate  arrangements  have  been  devised  for  the  mechan- 
ical part  of  the  process,  but  we  shall  confine  ourselves  to  the 
description  of  one  apparatus  which  everyone  is  likely  to  have, 
or  can  at  least  get  with  very  little  trouble.  The  first  requisite 
is  the  camera  in  which  the  original  negative  was  taken,  a  wet- 
plate  slide  fitting  that  camera,  or  a  double  slide  with  the  inter- 
nal partition  removed.  The  other  requisite  is  also  a  camera, 
this  time  a  quarter  plate  camera  of  the  simplest  description,  no 
motion  but  a  rack  and  pinion  for  focusing  being  required, 
fitted  with  a  short  focus  lens,  such  as  a  rectilinear  stereo  lens. 


THE    PROCESSES    OF    PURE    PHOTOGRAPHY. 


173 


The  front,  or  part  of  the  front  of  the  larger  camera  is  removed, 
and  the  small  camera  is  fitted  to  the  front  of  the  larger  cam- 
era, with  the  small  lens  protruding  into  the  larger  camera. 
We  figure  (Fig.  27)  our  own  arrangement,  as  fitted  up  by  our- 


FIG.  27. 

selves,  and  we  have  never  yet  found  circumstances  which  this 
did  not  suit.  The  lens  should  be  of  very  short  focus,  not  over 
four  inches  or  four  and  a  half  inches  focus,  and  must  be  recti- 
linear. The  negative  to  be  copied  goes  into  the  dark-slide  of 
the  larger  camera,  the  sensitive  plate  goes  into  the  dark-slide 
of  the  small  camera.  The  back  of  the  larger  camera  may  be 
pointed  towards  the  sky,  and  a  sheet  of  finely-ground  glass 
placed  about  one  or  two  inches  behind  the  negative ;  i.  e., 
between  the  negative  and  the  light ;  or  a  sheet  of  white  paper 


174         THE  PROCESSES  OF  PUKE  PHOTOGRAPHY. 

large  enough  to  illuminate  by  reflection,  the  whole  negative 
may  be  inclined  at  45  deg.  between  the  light  and  the  negative. 
The  amount  of  reduction  is  regulated  by  the  focusing  arrange- 
ment of  the  larger  camera,  different  parts  of  the  negative  may 
be  selected  for  copying  by  the  front  motions  of  the  larger 
camera,  and  focusing  is  performed  on  the  ground-glass  of  the 
small  camera,  preferably  with  a  Ramsden  eyepiece. 

The  exposure  with  ground-glass  behind  the  negative  may 
vary  at  -jC-  : 

With  Gelatine  Bromide  lantern  plates,  from  five  to  one 
hundred  and  twenty  seconds. 

With  Wet  Collodion,  from  thirty  seconds  to  ten  minutes. 

With  Dry  Collodion,  from  three  minutes  to  two  hours. 

We  have,  of  course,  gone  beyond  these  limits  in  both  direc- 
tions ;  the  table  is  given  merely  suggestively. 

Even  gelatine  chloride  plates  may  be  used  for  reduction  in 
the  camera,  the  exposure  being  very  long  if  the  negatives  are 
of  average  density.  Gelatine  chloride  emulsion  may  be  made 
more  sensitive  by  cooking,  but,  as  a  rule,  there  is  great  danger 
of  fogginess  from  this  proceeding. 

Gelatine  chloride  emulsion  for  lantern-slides  and  transparent 
positives.  Plates  prepared  with  this  emulsion  are  usually  ex- 
posed in  contact  with  the  negative,  for  a  few  seconds,  to  day- 
light. The  negative  is  placed  in  a  printing  frame  face  up- 
wards, and  the  chloride  plate  carefully  laid  on  the  negative 
film  to  film.  Mr.  A.  Cowan,  of  London,  has  favored  the  pub- 
lic with  some  very  fine  developing  formulae  for  such  plates, 
and  by  the  use  of  his  varied  proportions  and  ingredients  he 
produced  a  large  range  of  tones  on  his  plates. 

Iron  protosulphate 140  grains 

Sulphuric  acid 1  minim 

Water 1  ounce 

Add  one  part  of  this  to  three  parts  of  any  of  the  following, 
No.  1  giving  cold  tones,  No.  3  almost  crimson.  No.  3  requires 
much  more  exposure  than  No.  2,  and  No.  2  more  than  No.  1. 

1.  Potassic  citrate 136  grains 

Potassic  oxalate 44  grains 

Hot  water 1  ounce 


THE  PROCESSES  OF  PURE  PHOTOGRAPHY.         175 

2.  Citric  Acid 120  grains 

Ammonia  carbonate 88  grains 

Cold  water 1  ounce 

3.  Citric  acid 180  grains 

Ammonia  carbonate 60  grains 

Water 1  ounce 

The  following,  due  to  Mr.  B.  J.  Edwards,  gives  good  tones. 

a.  Neutral  potassic  oxalate 2  ounces 

Ammonium  chloride 40  grains 

Distilled  water 20  ounces 

b.  Iron  protosulphate , . 4  drams 

Citric  acid  2  drams 

Potash   alum 2  drams 

Water 20  ounces 

Mix  a  and  &  in  equal  proportions. 

Chloride  plates  should  develop  pretty  rapidly ;  if  the  image 
appears  to  develop  too  rapidly  add  a  few  drops  of  a  ten  per 
cent,  solution  of  common  salt.  Fix  in  hypo,  and  after  washing 
clear  with  a  saturated  solution  of  potash  alum,  acidulated  with 
sulphuric  acid. 

Glass  and  opal  plates  coated  with  this  emulsion  yield  beau- 
tiful positives,  when  printed  in  contact  and  treated  as  above. 

Lantern-Slides  ly  Dry  Collodion  Processes. — Supposing 
plates  to  be  coated  with  collodio-bromide  emulsion  prepared 
as  given  on  page  46,  et  seq.,  we  proceed  to  give  instructions 
how  these  plates  may  best  be  used  for  lantern-slides,  and 
we  may  say  that  it  is  extremely  doubtful  whether  for  really 
good  lantern-slides  with  clear  lights,  transparent  shadows,  and, 
above  all,  warm  tones,  this  process  can  be  surpassed. 

To  insure  the  warm  tones  on  which  we  so  much  insist,  the 
use  of  ammonia  is  contraindicated,  and  the  carbonates  coupled 
with  a  long  exposure  will  be  found  best.  The  formulae  we 
give  are  due  mostly  to  Mr.  W.  Brooks,  of  Keigate,  who  pre- 
pares emulsion,  and  with  it  slides  not  easily  equaled. 

PYRO  SOLUTION. 

Pyrogallol 96  grains 

Alcohol 1  ounce 


176  THE   PROCESSES   OF   PUEE   PHOTOGRAPHY. 

ALKALINE  SOLUTIONS. 

1.  Saturated  solution  of  ammonia  carbonate 4  ounces 

Potassic  bromide 60  grains 

Sodic  acetate 120  grains 

Water 8  ounces 

2.  Potassic  carbonate 360  grains 

Potassic  bromide 60  grains 

Sodic  acetate 120  grains 

Water 12  ounces 

3.  Potassic  carbonate 300  grains 

Potassic  bicarbonate 150  grains 

Potassic  bromide 60  grains 

Sodic  acetate 120  grains 

Water 12  ounces 

No.  1  requires  the  longest  exposure,  and  gives  the  warmest 
tones  ;  the  ammonium' carbonate  must  be  fresh  and  pure,  and 
for  saturation  should  be  left  several  days  in  water,  getting  an 
occasional  shaking.  After  this  some  of  the  crystals  must  be 
left  at  the  bottom  of  the  bottle.  No.  2  is  a  more  powerful  alka- 
line solution  than  No.  1,  and  requires  much  less  exposure. 
The  tones  given  by  No.  2  are  not  so  good  as  those  of  No.  1. 
Nos.  1  and  3,  mixed  in  equal  quantities,  give  a  grand  chestnut 
tone  with  a  moderate  exposure. 

After  exposure  the  plate  is  flowed  in  yellow  light  with  a 
mixture  of  methylated  spirits  and  water  in  equal  parts.  This 
is  allowed  to  act  on  the  film  for  about  a  minute,  and  is  then 
washed  off.  The  plate  may  either  be  immersed  in  the 
developer  in  a  dish  or  held  in  the  hand  by  a  pneumatic  holder, 
and  the  developer  flowed  over  it.  Development  is  not  so 
quick  as  with  a  gelatine  plate ;  the  image  appears  faint  at  first, 
with  details,  perhaps,  all  over,  and  density  is  gained  very 
gradually. 

The  developer  consists  of 

Pyro  solution,  as  above 20  minims 

One   of  the  alkaline  solutions,  or  a  mixture  of 

two  of  them 2  drams 

Water 2  drams 

The  developer  must  not  be  poured  off  and  on  at  first,  but  as 
details  and  density  increase  pouring  off  and  on  may  be  resorted 


THE   PROCESSES    OF   PURE    PHOTOGRAPHY.  177 

to  as  a  local  intensification.  Development  to  full  density  may 
occupy  five  or  six  minutes,  and  the  plate  is  then  to  be  washed 
and  fixed  with  hypo,  or,  preferably,  potassic  cyanide,  20 
grains  ;  water,  1  ounce.  Ee-development  may  be  resorted  to 
with  pyro  and  silver,  as  follows,  but  we  do  not  like  it,  as  the 
shadows  are  apt  to  get  blocked  up. 
Ee-developer  (which  may  also  be  used  later  as  an  intensifier): 

Pyrogallol 30  grains 

Citric  acid 30  grains 

Alum 30  grains 

Water 15  ounces 

Flow  a  sufficient  quantity  of  this  over  the  plate,  then  return 
it  to  the  cup  to  which  meantime  have  been  added,  for  every 
two  drams  of  the  pyro  and  acid  solution,  two  or  three  drops  of 
a  twenty-grain  solution  of  silver  nitrate.  This  is  to  be  poured 
on  and  off  the  plate,  but  the  instant  any  cloudiness  appears  the 
solution  must  be  rejected  and  a  fresh  quantity  made  if  neces- 
sary. 

To  get  various  fine  tones  more  nearly  approaching  the  blues 
the  plate  may  be  toned  with : 

Platinic  chloride 1  grain 

Nitric  acid 1  minim 

Water 3  ounces 

The  plate  may  be  removed  when  a  warm  brown  tone  is 
arrived  at,  or  at  any  other  desired  stage,  but  to  produce  a  very 
fine  engraving  black  tone  the  plate  may  be  left  in  the  platinum 
solution  till  the  image  is  almost  gone,  or  very  gray ;  it  is  then 
to  be  washed  and  intensified  with  the  pyro  intensifier  given. 
Though  we  do  not  like  re-development,  we  recommend  intensi- 
fication after  fixing  by  this  acid-alum-pyro  solution,  which  is 
due  to  Mr.  Brooks,  and  gives  very  fine  tones  indeed. 

Any  slight  veil  or  fog  on  a  collodion  positive  may  be 
removed  by  flowing  over  it  several  times  a  strong  colored 
solution  of  iodine  made  by  adding  water  to  the  "  tincture." 
Silver  iodide  is  formed,  and  cyanide  solution,  as  for  fixing, 
will  clear  the  plate  at  once. 

Collodion  slides  and  positives  for  window  decoration,  which 


178  THE   PROCESSES    OF   PURE   PHOTOGRAPH r. 

may  be  made  equally  with  slides  by  the  above  process,  should  be 
varnished  with  a  clear  white  varnish  (see  formulae  at  the  end). 
Wet  collodion  for  lantern-slides.  We  have  pointed  out 
in  Chapter  VI.  a  suitable  method  of  making  slides  by  this 
process.  The  platinum  toning  bath  may  be  used  as  above,  or 
the  following,  due  to  Mr.  T.  N.  Armstrong,  an  amateur  of 
Glasgow : 

Palladium  chloride . . : 15  grains 

Water 15  ounces 

For  each  ounce  of  water  required  to  cover  the  slide  in  a 
dish  take  one  dram  of  the  above.  Leave  the  slide  in  this  till 
the  tone  has  reached  the  back  of  the  film,  as  seen  through  the 
glass  plate.  If  any  dense  parts  refuse  to  tone,  pour  the  solu- 
tion on  to  them  several  times  from  a  slight  height.  Eight  or 
ten  minutes  should  suffice  to  tone  a  plate  by  this  method,  and 
the  tone  is  not  only  unique  but  highly  pleasing, 

Gelatine  Bromide  for  Lantern-Slides, — In  the  chapter  on 
slow  gelatine-bromide  emulsion  will  be  found  directions  for 
making  an  emulsion  eminently  suitable  for  the  purpose  of 
lantern-slide  preparation.  We  may  say  that  the  "slower"  the 
•emulsion  the  more  likely  it  will  be  to  give  good  slides  in  the 
beginner's  hands.  The  gelatine-bromide  plates  usually  put  on 
the  market  for  this  purpose  are,  in  our  opinion,  too  rapid  and 
too  liable  in  unskilled  hands  to  give  foggy  slides,  which  of  all 
kind  of  slides  are  the  worst  and  the  commonest.  The  ex- 
posure, whether  by  contact,  or  in  the  camera,  must  be  such  that 
no  forcing,  or  abnormal  quantity  of  alkali,  is  required  in  develop- 
ment ;  further  we  need  not  go. 

For  development  the  ferrous  oxalate  may  be  used,  keeping 
the  proportion  of  iron  low,  and  using  a  proportion  of  soluble 
bromide  (say  half  a  grain  to  each  ounce  of  a  developer  con- 
sisting of  potassic  oxalate  solution,  as  given  elsewhere  (page  92), 
six  parts,  iron  solution  one  part). 

Mr.  Carbutt,  U.  S.  A.,  gives  a  formula  which  will  be  found 
to  work  well  with  many  plates. 

a.  Potassic  oxalate 8  ounces 

Water 30  ounces 

Citric  acid. . .    .    60  grains 

Citrate  of  ammonia  solution. ..                                   .  2  ounces 


THE   PKOCESSES    OF   PUKE    PHOTOGRAPHY.  179 

b.  Ferrous  sulphate 4  ounces 

Water 32  ounces 

Sulphuric  acid 8  minims 

The  citrate  of  ammonia  solution  is : 

Dissolve  citric  acid 1  ounce 

Water 5  ounces 

Add  liquor  ammonia  till  neutral,  make  up  to  eight  ounces. 
The  developer  consists  of 

a 2  ounces 

b 1  ounce 

10  per  cent  solution  of  potassic  bromide 5  minims 

Mr.  Edward's  hydrochinon  developer  acts  well.  It  will  be 
found  quoted  on  page  145. 

"Where  a  warm  tone  is  required,  undoubtedly  the  best  de- 
veloper is  alkaline  pyrogallol.  But  sodic  sulphite  must  not 
form  an  ingredient  of  the  alkaline  pyro  developer,  we  have 
never  liked  the  tone  peculiar  to  that  salt,  and  we  have  never 
yet  been  able  entirely  to  prevent  the  peculiar  tone  given  by  that 
salt  from  appearing  in  our  slides.  Very  much  superior,  in  our 
estimation,  for  this  purpose,  if  for  no  other,  is  the  potassic 
bisulphite,  which  first  caught  our  attention  in  a  formula  pro- 
mulgated by  Messrs.  Mawsan  and  Swan,  of  Newcastle.  The 
salt  was,  in  this  formula,  called  "  meta-bisulphite ;"  we  have 
never  yet  met  a  satisfactory  account  of  this  name,  and  we  find 
ordinary  potassic  bisulphite  precisely  the  same  in  action  as  in 
appearance  and  odor.  "We  shall,  however,  give  Messrs.  Maw- 
san and  Swan's  own  formula,  leaving  the  reader  to  use  the 
"  meta,"  if  he  can  get  it,  or  omit  the  "  meta,"  if  it  is  not  forth- 
coming. 

a.  Pyrogallol 40  grains 

Potassic  meta-bisulphite  120  grains 

Water 20  ounces 

b.  Liquor  ammonia  fort 2^  drams 

Ammonium  bromide 40      grains 

Water 10      ounces 

To  develop  mix  a  and  b  in  equal  proportions.  "With  any  of 
these  developers  the  image  should  begin  to  appear  after  the 


180         THE  PROCESSES  OF  PUKE  PHOTOGRAPHY. 

plate  has  been  in  the  solution  about  forty-five  seconds  or  a 
minute.  There  should  be  no  rushing  up  of  details  or  density. 
Yery  pretty  little  glass  dishes  may  be  obtained  for  developing 
slides ;  they  must  be  kept  scrupulously  clean ;  a  stain  that 
would  never  be  noticed  on  a  negative,  may  be  ruin  to  so  deli- 
cate a  picture  as  a  lantern-slide  should  be. 

We  give  one  more  pyro  developer,  which  may  be  called  a 
standard  developer ;  it  works  well  with  every  good  plate  we 
have  yet  met. 

a.  Solution  of  pyro,  preserved  with  citric  acid,  20 

grains  to  each  ounce 10  per  cent 

b.  Ammonia 10  per  cent 

c.  Bromide  (amm.  or  pot.) 10  per  cent 

DEVELOPER. 

a 20  minims 

•     b 20  to  25  minims 

c 20  minims 

Water 1  ounce 

Fixing  is  done  with 

Sodic  hyposulphite 1  part 

Water 5  parts 

After  fixing,  a  scum  is  frequently  noticed  on  slides.  Strong 
solution  of  alum,  acidified  with  sulphuric  acid,  poured  on 
and  off,  will  almost  always  remove  the  scum.  Mr.  Edwards 
recommends  the  addition  of  ferrous  sulphate  to  the  alum  and 
acid.  If  the  plate,  after  fixing,  be  not  washed,  but  merely 
rinsed  under  the  tap,  a  fine  warm  tone  may  be  produced  by 
pouring  on  a  solution  of  the  following  nature : 

Alum   (potash)   concentrated    solution,    containing 

citric  acid  to  saturation 1  ounce 

Iron  protosulphate,  saturated %  ounce 

The  warm  tone  produced  may  be  suspected  of  fugitiveness, 
but  we  find  it  permanent. 

Eastman's  transferotype  process  yields  fine  slides.  (See  page 
147.)  The  development  is  conducted  as  usual,  preferably  with 
ferrous  oxalate,  and  the  finished  paper  film  is  squeegeed 
to  a  piece  of  glass  of  the  required  size,  and  scrupulously  clean. 


THE   PROCESSES   OF   PURE   PHOTOGRAPHY.  181 

If  the  plates  are  just  3^  inches  square,  the  prints  should,  before 
being  squeegeed,  be  trimmed  slightly  smaller,  as  the  edges  of 
the  paper  must  not  overlap  the  glass.  After  stripping,  which 
must  not  be  attempted  until  at  least  half  an  hour  has  elapsed 
after  squeegeeing,  the  plate  is  cleared  with  alum  and  acid, 
washed  and  dried.  All  slides  should  be  varnished  with  clear 
or  "crystal "  varnish. 

To  Mount  Lantern-Slides. — Articles  required:  Masks  of 
variously  shaped  apertures ;  "  strips "  to  gum  round  edges  ; 
clean  and  thin  glasses  3£  inches  square.  The  cover-glasses 
should  be  free  from  imperfections,  as  bubbles.  The  shape  of 
the  mask  apertures  is  a  matter  not  sufficiently  attended  to. 
Mr.  J.  W.  Champney  contributed  to  a  New  York  society  some 
remarks  which  deserve  attention.  The  masks  must  be  opaque. 
A  very  good  paper  for  the  purpose  is  white  on  one  side  and 
black  on  the  other,  the  white  side  being  utilized  for  writing 
the  names  of  the  subjects.  "  Strips  "  are  sold  ready-gummed. 
As  a  rule,  these  cannot  be  trusted  to  stick  long,  and  the  safer 
plan  is  to  get  plain  strips  of  "  needle-paper  "  about  14  inches 
long,  and  at  the  time  of  use  to  cover  each  strip  with  thin  glue, 
to  which  is  added  a  small  quantity  of  oil  of  lavender,  a  hint 
for  winch  we  have  to  thank  the  illustrious  Mr.  George  Wash- 
ington Wilson,  of  Aberdeen.1 

The  slide  being  finally  mounted  requires  some  mark,  so  that 
the  lantern  operator  may  know  at  a  sjlance  which  way  to  put 
it  into  the  lantern.  Lay  the  slide  down  on  the  table  as  the  view 
appeared  in  nature,  and  at  each  of  the  two  top  corners  place 
a  small  disc  of  gmnmed  paper,  white  on  a  black  mask,  and  vice 
versa. 


CHAPTER  XXXI. 
RESIDUES. 

AMATEURS,  who  find  their  hobby  somewhat  expensive,  and 
professionals,  whose  yearly  returns  are  not  as  large  as  might 
be  desired,  will  do  well  to  preserve  carefully  all  material  con- 
taining noble  metals  in  any  shape.  A  very  small  percentage 
of  the  silver  originally  used  in  the  preparation  of  sensitive 
substances  is  present  in  the  finished  negative  or  print.  We 
have  seen  it  stated  that  a  print  on  albumenized  paper  contains 
only  about  3  per  cent,  of  the  silver  originally  present  in  it. 
We  do  not  guarantee  the  accuracy  of  this  estimate,  but  it  is 
probably  not  -very  far  wide  of  the  mark. 

The  following  should  always  be  carefully  preserved :  1st.  All 
paper  containing  or  bearing  silver  salts,  as  trimmings  of  un- 
toned  albumenized  paper,  bromide  and  chloride  papers,  filter 
papers  used  for  silver  solutions.  2d.  Water  wherein  prints 
containing  free  silver  nitrate  have  been  washed.  3d.  Old 
toning  baths.  4th.  Old  fixing  baths.  5th.  Waste  emulsions  of 
any  kind. 

1.  Paper  Residues.     After  a  considerable  quantity  of  waste 
paper  has  been  collected,  it  should  be  burned  completely  to 
fine  ashes.     An  ordinary  stove  or  grate  will  answer  for  burn- 
ing, provided  the  draught  do  not  carry  away  the  very  light 
ashes. 

2.  Washing  Waters.    The  first  two  waters  used  for  washing 
sensitized  albumenized  paper  should  be  put  into  a  reservoir 
with  a  tap  about  four  to  six  inches  from  the  bottom.    When  the 
vessel  is  pretty  full,  hydrochloric  acid  may  be  used  to  acidify 
the  residue,  and  the  silver  may  be  thrown  down  as  chloride  by 
the  addition  of  a  quantity  of  concentrated  solution  of  sodic 
chloride — common  salt.     Hydrochloric  acid  may  be   used  to 


THE  PROCESSES  OF  PURE  PHOTOGRAPHY.         183 

throw  down  all  the  silver,  but  we  prefer  the  salt.  If  too  much 
salt  be  added,  the  chloride  will  be  re-dissolved.  When  the 
chloride  is  all  down,  the  supernatant  liquid  is  drawn  off  by  the 
tap,  or  siphoned  off,  or  even  baled  off.  The  chloride  is  col- 
lected, washed  in  water,  dried,  and  added  to  the  paper  ashes. 

3.  Old  Toning  Baths.     In  a  toning  bath  the  gold  may  be 
inert  as  a  toning  substance  but  can  be  saved.     The  bottle  con- 
taining a  toning  bath  often  becomes  encrusted  with  a  deposit 
of  gold ;  this  may  be  dissolved  by  aqua  regia  and  added  to 
the  bulk  of  old  baths.     The   bulk  being   acidified  with  sul- 
phuric acid,  a  saturated  solution  of  ferrous  sulphate  is  added 
till  no  more  gold  is  precipitated.     The  precipitate  is  collected, 
washed,  dried,  and  may  either  be  added  to  Nos.  1  and  2,  or 
kept  separate. 

4.  Old  Fixing  Baths  are  usually  the  most  valuable  of  all 
residues.    Every  plate,  whether  exposed  or  gone  wrong  before? 
during  or  after  exposure,  should  be  "  fixed."     The  used  fixing 
baths  are  to  be  preserved  in  a  vessel  similar  to  that  used  for 
No.  2.     The  solution  should  be  acidified  with  sulphuric  acid, 
and  precipitation  of  the  silver  effected  by  the  addition  of  a 
strong  solution  of  potassic  sulphide,  "  liver  of  sulphur."    This, 
however,  must  not  be  done  in  the  operating,  nor,  indeed,  in 
any  inhabited  room ;  but  in  the  open  air,  for  the  odor  is  both 
unpleasant  and  unwholesome.     As  an  alternative,   strips  of 
zinc  or  copper  may  be  suspended  in  the  old   hypo  solution, 
when  the  silver  will  be  precipitated  on  the  strips  or  on  the 
vessel.     When  the  precipitation   is   complete,  the  deposit  is 
collected,  washed,  dried,  and  kept  separate  from  other  residues. 

5.  Old  Emulsions,  if  of  collodion,  may  be  poured  out  to  set 
in ;  a '  flat  dish,   allowed  to    desiccate,  lifted  or  scraped  from 
the  dish,   and  added  to   the    paper   ashes,   or  the   chlorides. 
If  of  gelatine,  they  should  be  treated  in  one  of  the  following 
ways :  Add  to  the  waste  emulsion,  in  a  large  iron  pot,  five 
times  its  weight  of  caustic  alkali  and  boil  for  half  an  hour. 
The  boiling  will  be  very  furious  at  first,  but  will  subside  after 
a  little.     Or  several  times  its  bulk  of  sulphuric  acid  may  be 
added  to  the  emulsion  and  the  whole  boiled  for  a  few  minutes. 
In  each  case  the  gelatine  will  be  deprived  of  its  setting  power 


184  THE   PROCESSES    OF   PURE    PHOTOGRAPHY. 

or  viscous  quality,  and  the  silver  in  whatever  state  it  is  will 
settle  to  the  bottom  and  can  be  separated  by  decantation  from 
the  liquid.  It  may  then  be  washed  and  added  to  the  chlorides. 

Platinum  residues  are  very  valuable  and  may  be  saved  thus : 
All  waste  paper  should  be  passed  through  the  developing 
solution.  Old  potassic  oxalate  developing  solutions  are  col- 
lected and  boiled  with  one-fourth  of  their  volume  of  ferrous 
sulphate.  The  platinum  separates  and  can  be  collected  on  a 
filter. 

We  do  not  advise  the  reader  to  fuse  his  own  residues  as  a 
matter  of  business,  for  a  professional  refiner  will  get  much 
more  noble  metal  out  of  them  than  the  photographer  is  likely 
to  do.  As  an  interesting  experiment,  however,  the  following 
may  be  tried.  Take  the  paper  ash  and  the  chlorides,  with  which 
may  be  included  the  gold,  dry  all  thoroughly  and  mix  with 
a,  flux  consisting  of  four  times  the  weight  of  the  chlorides  of  a 
mixture  in  equal  parts  of  the  carbonates  of  soda  and  potash. 
Mix  thoroughly  and  put  into  a  crucible,  subjecting  it  to  white 
heat  till  the  contents  of  the  crucible  are  perfectly  liquid. 
Then  either  pour  out  on  to  a  cold  stone  floor,  or  allow  to  cool 
and  break  the  crucible.  In  one  case  a  bar,  in  the  other  a  button 
of  silver,  will  be  found.  If  gold  is  present  a  refiner  will 
allow  for  it. 


THE  PROCESSES  OF  PUKE  PHOTOGRAPHY.         185 


FORMULAE  RECOMMENDED. 


Varnish  for  gelatine  negatives  ("British  Journal  Alma- 
nac.") 

Best  Orange  Shellac \%  ounce 

Methylated  alcohol 1      pint 

Keep  in  a  warm  place  till  dissolved,  then  add  a  large  tea- 
spoonful  of  whiting  or  prepared  chalk ;  set  aside  to  clear ; 
decant. 

Plate  to  be  heated  before  and  after  application. 

GROUND  GLASS  OR  "  MATT"  VARNISH. 

Sandarac 90  grains 

Mastic 20  grains 

Ether 2  ounces 

Benzole ^  to  1)^  ounces 

More  benzole  added  finer  the  matt  obtained. 
This  varnish  to  be  applied  cold. 

GELATINE  BROMIDE  PROCESSES — DEVELOPERS. 
EDWARD'S  GLYCERINE  DEVELOPER. 

a.  Pyro 1  ounce 

Glycerine 1  ounce 

Methyl  alcohol 6  ounces 

Mix  spirits  and  glycerine,  then  add  pyro. 

a.  One  part  of  this  to  fifteen  of  water. 

b.  Potassic  bromide 60  grains 

Liq.  Amm.  .880 1  ounce 

Glycerine 1  ounce 

Water Bounces 

b.  One  part  of  this  to  fifteen  of  water. 
Developer  :  Equal  parts  of  the  above,  a  and  I. 

MR.  WOLLASTON'S  MODIFICATION  OF  THE  EASTMAN  DEVELOPER  FOR 
PAPER  NEGATIVES 

a.  Sodic  sulphite  pure 8  ounces 

Hot  distilled  water  . .  40  ounces 


186  THE   PROCESSES    OF   PUKE   PHOTOGRAPHY. 

Cool  to   60   deg.  Fahr.     Make  just  acid  with  citric  acid. 
Pour  on  to  one  ounce  of  pyro. 

b.  Sodic  carb 4  ounces 

Potassic  carb 1  ounce 

Distilled   water 40  ounces 

Equal  parts  of  a  and  b. 

A  SIMPLE  DEVELOPER  FOR  GELATINE   BROMIDE. 

a.  Pyro 40  grains 

Added  to, 

Water 10  ounces 

In  which  is  dissolved 

Citric  acid 10  grains 

b,  Liq.  Amm.  .880 1  dram 

Amm.  brom 25  grains 

Water 10  ounces 

Equal  parts  of  a  and  b. 

HYDROCHINON  DEVELOPER. 

a.  Hydrochinon 20  grains 

Water 10  ounces 

Sodic  sulphite 10  grains 

Dissolved  together  first. 

b.  Carbonates  according  to  Wollaston  above  or  to  formula  in  text. 

CLEARING  SOLUTIONS  FOR  GELATINE  BROMIDE  PLATES. 

MR.  EDWARDS'. 

Alum 1  ounce 

Citric  acid 1  ounce 

Sulphate  of  iron 3  ounces 

Water 20  ounces 

Another : 

Alum Bounces 

Hydrochloric  acid ^  ounce 

Water 20  ounces 

INTENSIFYING  SOLUTIONS  FOR  GELATINE  PLATES. 

a.  Mercuric  chloride 1  part 

Ammonic  chloride 1  part 

Water 20  parts 


THE   PROCESSES    OF   PURE    PHOTOGRAPHY.  187 

Bleach  thoroughly,  wash  thoroughly,  then  pour  on 

b.  Liquid  ammonia 1  part 

Water 20  parts 

Or, 

Sodic  hyposulphite 1  part 

Water lOJparts 

Or, 

Sodic  sulphite , 1  part 

Water 5  parts 

URANIUM  INTENSIFIER. 

a.  Uranium  nitrate  in  water 1  per  cent. 

b,  Potassic  ferricyanide  in  water 2  per  cent. 

Flood  the  plate  with  #,  then  mix  in  5. 

TONING  BATHS. 

BLACK  TONES  (MR.  SCHOLZIG). 

Sodic  tungstate 30  grains 

Boiling  water 3  ounces 

Dissolve,  then  add 

Gold  chloride 1  grain 

Water  to Bounces 

PHOSPHATE  BATH. 

Sodic  phosphate 30  grains 

Gold  chloride 1  grain 

Water Bounces 

Does  not  keep  well. 


188 


THE    PROCESSES   OF   POKE    PHOTOGRAPHY. 


TABLE  OF  ATOMIC  AND  MOLECULAR  WEIGHTS  OF  THE 
ELEMENTS. 


(Derived  from  Professor  F.  W.  Clarke's  figures.) 


NAMES  AND  SYMBOLS. 

WEIGHTS. 

wK 

NAMES  AND  SYMBOLS. 

WEIGHTS. 

wfht* 

Aluminum,  Al.  .  .. 
Antimony,  Sb.  .  .  . 

27.0090 
119.9550 
74  9180 

27. 
120. 
74  9 

Nickel,  Ni  
Niobium,  Nb  

57.9280 
93.8120 
14  0210 

57.9 
93.8 
14 

Barium,  Ba  
Bismuth,  Bi  
Boron,  Bo  
Bromine,  Br  
Cadmium,  Cd.  .  .  . 
Csesium,  Cs  

136.7630 
207.5230 
10.9410 
79.7680 
111.8350 
132.5830 

136.8 
207.5 
10.9 
79.8 
111.8 
132.6 

Osmium,  Os  
Oxygen,  O  
Palladium,  Pd  .  .  . 
Phosphorous,  P.  .  . 
Platinum,  Pt  
Potassium,  K  

198.4940 
15.9633 
105.7370 
30.9580 
194.4150 
39.0190 

198.5 
16. 
105.7 
31. 
194.4 
39. 

Calcium,  Ca  
Carbon,  C  

39.9900 
11.9736 

40. 

12. 

Rhodium,  Rh  
Rubidium,  Rb  

104.0550 
85.2510 

104.1 
85.3 

Cerium,  Ce  

140.4240 

140.4 

Ruthenium,  Ru.. 

104.2170 

104.2 

Chlorine,  Cl 

35  3700 

35  4 

43  9800 

44. 

Chromium,  Cr.  .  .  . 
Cobalt,  Co  
Copper  Cu 

52.0090 
58.8870 
63  1730 

52. 

58.9 
63  2 

Selenium,  Se  
Silicon,  Si  

78.7970 
28.1950 
107  6750 

78.8 
28.2 
107.7 

Didymium,  D.  .  .  . 
Erbium,  E  
Fluorine,  Fl  
Gallium,  Ga  
Glucinum,  G.  .  .  ,. 
Gold,  Au  
Hydrogen,  H  
Indium,  In  
Iodine,  I  

144.5730 
165.8910 
18.9840 
68.8540 
9.0850 
196.1550 
1.0000 
113.3980 
126.5570 

144.6 
165.9 
19. 
68.9 
9.1 
196.2 

1- 

113.4 
126.6 

Sodium,  Na  
Strontium,  Sr  .  .  . 
Sulphur,  S  
Tantalum,  Ta  
Tellurium,  Te  
Thallium,  Tl  
Thorium,  Th  
Tin,  Sn  
*Titanium,  Ti.  .  .  . 

22.9980 
87.3740 
31.9840 
182.1440 
127.9600 
203.7150 
233.4140 
117.6980 
47.0997 

23. 

87.4 
32. 
182.1 
128. 
203.7 
233.4 
117.7 
48. 

Iridium,  Ir  
Iron,  Fe  
Lanthanum  La.  .  .. 
Lead,  Pb  
Lithium  Li  .. 

192.6510 
55.9130 
138.5260 
206.4710 
7.0073 

192.7 
55.9 
138.5 
206.5 

7. 

Tungsten,  W  
Uranium,  U  
Vanadium,  Va.  .  .. 
Ytterbium,  Yb.  .  . 
Yttrium,  Y  

183.6100 
238.4820 
51.2560 
172.7610 
89.8160 

183.6 
238.5 
51.3 

172.8 
89.8 

Magnesium,  Mg.  . 
Manganese,  Mn.  .. 
Mercury,  Hg  
Molybdenum,  Mo 

23.9590 
53.9060 
199.7120 
95.5270 

24. 
53.9 
199.7 
95.5 

Zinc,  Zn  
Zirconium,  Zr.  .  .  . 

64.9045 
89.3670 

64.9 
89.4 

'•  Thorpe,  T.  E.,  Chemical  News,  48  ;  251. 


THE   PROCESSES   OF   PURE    PHOTOGRAPHY.  189 


o  S^^wc.*.^  "w^w^"1:  £„«»  8  8  " 

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190 


TBE   PROCESSES   OF   PUKE   PHOTOGRAPHY. 


METRIC  SYSTEM  OF  WEIGHTS  AND  MEASURES. 

MEASURES  OF  LENGTH. 


DENOMINATIONS  AND  VALUES. 

EQUIVALENTS  IN  USE. 

Myriameter  
Kilometer  

10,000  meters. 
1,000  meters. 
100  meters. 
10  meters. 
1  meter. 
l-10th  of  a  meter. 
l-100th  of  a  meter. 
l-1000th  of  a  meter. 

6.2137    miles. 
.62137  mile,  or  3,280  ft. 
328.           feet  and  1  inch. 
393  7         inches. 
39  37       inches. 
3  937      inches. 
3937    inch. 
0394    inch. 

10  ins. 

r)pkarn«>ter, 

Meter  
Decimeter  
Centimeter  
Millimeter  

MEASURES  OF    SURFACE. 


DENOMINATIONS  AND  VALUES. 

EQUIVALENTS  IN  USE. 

Hectare  '.  

10,000  square  meters. 
100  square  meters. 
1  square  meter. 

2.471  acres. 
119.6      square  yards. 
1,550.        square  inches. 

Are                         

MEASURES  OF  VOLUME. 


DENOMINATIONS  AND  VALUES. 

EQUIVALENTS  IN  USE. 

NAMES. 

No.  OF 
LITERS. 

CUBIC  MEASURES. 

DRY  MEASURE. 

WINB  MEASURE. 

Kiloliter  or  stere 
Hectoliter  

Dekaliter  
Liter 

1,000 
100 

10 
1 
1-10 
1-100 
1-1000 

1  cubic  meter. 
l-10th  cubic  meter. 

10  cubic  decimeters. 
1  cubic  decimeter. 
l-10th  cubic  decimeter. 
10  cubic  centimeters. 
1  cubic  centimeter. 

1.308   cubic  yards. 
2          bu.  and  3.35 
pecks. 
9.08     quarts. 
.908   quart. 
6.  1022  cubic  inches. 
.6102  cubic  inch. 
.061    cubic  inch. 

264.17        gallons. 

26.417      gallons. 
2.6417    gallons. 
1.0567    quarts. 
.845     gill. 
.  338      fluid  oz. 
.27       fl.  drm. 

Deciliter  
Centiliter  
Milliliter  

WEIGHTS. 


DENOMINATIONS  AND  VALUES. 

EQUIVALENTS 
IN  USE. 

NAMES. 

NUMBER 
OF  GRAMS. 

WEIGHT  OF  VOLUME  OF  WATER 
AT  ITS  MAXIMUM  DENSITY. 

AVOIRDUPOIS 
WEIGHT. 

Millier  or  Tonneau  

1,000,000 
100,000 
10,000 
1,000 
100 
10 

1 

1-10 
1-100 
1-1000 

1  cubic  meter. 
1  hectoliter. 
10  liters. 
1  liter. 
1  deciliter. 
10  cubic  centimeters. 
1  cubic  centimeter. 
l-10th  of  a  cubic  centimeter. 
10  cubic  millimeters. 
1  cubic  millimeter. 

2204.6        pounds. 
220.46      pounds. 
22.046    pounds. 
2.2046  pounds. 
3.5274  ounces. 
.3527  ounce. 
15.432    grains. 
1.5432  grain. 
.1543  grain. 
.0154  grain. 

Myriagram  
Kilogram  or  Kilo        

TVkagrram       ...  ,  ,    ,    . 

Gram  
Decigram  
Centigram  
Milligram  

For  measuring  surfaces^  the  square  dekameter  is  used  under  the  term  of  ARE  ;  the 
hectare,  or  100  ares,  is  equal  to  about  two  acres.  The  unit  of  capacity  is  the  cubic  decime- 
ter or  LITER,  and  the  series  of  measures  is  formed  in  the  same  way  as  in  the  case  of  the 
table  of  lengths.  The  cubic  meter  is  the  unit  of  measure  for  solid  bodies,  and  is  termed 
STERE.  The  unit  of  weight  is  the  GRAMME,  which  is  the  weight  of  one  cubic  centi- 
meter of  pure  water  weighed  in  a  vacuum  at  the  temperature  of  4  deg.  Cent,  or  39.2  deg. 
Fahr.,  which  is  about  its  temperature  of  maximum  density.  In  practice,  the  term  cubic 
centimeter,  abbreviated  c.c.,  is  used  instead  of  milliliter,  and  cubic  meter  instead  of  kilo- 
liter. 


THE    PROCESSES    OF   PURE   PHOTOGRAPHY. 


191 


UNITED  STATES  WEIGHTS  AND  MEASURES. 

ACCORDING  TO  EXISTING  STANDARDS. 


12  inches  =  1  foot. 

3  feet  =  1  yard. 
5.5  yards  =  rod. 
40  rods  =  1  furlong. 

8  furlongs  =  1  mile. 


144  sq.  ins.  =  1  sq.  ft. 
9  sq.  ft.  =  1  sq.  yd. 
30.25  sq.yds.=  lsq.  rod. 
40  sq.rods.=  1  sq.rood. 
4  sq.  roods  =  1  acre. 
640  acres  1  sq.  mile. 


Feet.      Yards.  Rods.  Furlong. 


LINEAL. 

Inches. 
12 

36=         3 

198  =       16.5  =         5.5 
7,920  =     660     =     220  =    40 
63,360  =  5,280     =  1,760  =  320  =  8 


Rods.     Roods.  Acres. 


SURFACE— LAND. 

Ft.  Yds. 

9=1 

272.25  =         30.25  =  1 

10,890  =         1,210  =  40  =         1 

43,560  =         4,840  =         160  =         4=1 
27,878,400  =  3,097,600  =  102,400  =  2,560  =  640 

VOLUME— LIQUID. 


4  gills  =  1  pint. 
2  pints  =  1  quart. 
4  quarts  =  1  gallon. 


Gills.    Pints.    Cub.  In. 

8 
32    =     8    =    231 


Gallon.       Pints. 

1     =        8     = 

1     = 


Ounces. 
128     = 
16     = 
1     = 


FLUID. 

Drams 

Minims.       Cubic  Centimetres. 

1,024 

= 

61,440     = 

3,785.441 

128 

s— 

7,680    = 

473.180 

8 

= 

480    = 

29.574 

1 

= 

60     = 

3.697 

16  ounces,  or  a  pint,  sometimes  called  a  pound. 


Pound. 
1 


Ib. 

Pound. 
1 


Ounces. 

12 

1 


TROY   WEIGHT. 

Pennyweights. 

240  = 

=  20  = 

1  = 


Grains. 
5,760 
480 
24 


APOTHECARIES'  WEIGHT. 


Ounces. 
12 

1 


3 

Drams. 

96 

8 

1 


3  gr- 

Scruples.  Grains. 

288       =  5,760 

24       =  480 

3       =  60 

1       =  20 
1 


Grams. 

373.25 

31.10 

1.55 


Grams. 

373.25 

31.10 

3.89 

1.30 

.06 

1.00 


The  pound,  ounce,  and  grain  are  the  same  as  in  Troy  weight. 
AVOIRDUPOIS  WEIGHT. 

Pound.              Ounces.               Drams.                Grains  (Troy).  Grams. 

1          =          16          =          256          =              7,000     '       =  453.60 

1          =            16          =                 437.5        =  28.35 

1          =                   27.34      =  1.77 


192 


THE   PROCESSES   OF   PURE   PHOTOGRAPHY. 


TABLES  FOE  THE   CONVERSION   OF  GRAMS  (OR  CUBIC 
CENTIMETRES)   INTO   OUNCES  AND   GRAINS. 


CONVERSION   OF  GRAMS  INTO 
GRAINS. 
Grams.                                                Grains. 

15  43 

CONVERSION  OF  GRAINS   INTO 
GRAMS. 
Grains.                                                  Grams. 
1                                             0648 

30.86 

2  1296 

46.29 
.  .    61  78 

3 

1944 

4  

K 

2592 
.   .    8240 

77  16 

92  59 

6  """ 

3888 

7  . 

...  108  08 

7  
8  
9 

::::::::::::::::.::..:::...:  ^ 

5184 
..    .5832 

g 

123  46 

9.... 

..  138.89 

CONVERSION  OF  GRAMS  INTO 
TROY  OUNCES. 
Grams.                                     Troy  Ounces. 

1                                                                                    03215 

CONVERSION  OF  GRAMS  INTO 
AVOIRDUPOIS  OUNCES. 
Grams.                          Avoirdupois  Ounces. 

1                                                                              03527 

| 

06430 

2. 

8 

rmftt 

8    

09645 

10581 

4 

12860 

4 

14108 

5  

16075 

5 

17635 

6  
7                             .  . 

19290 
.     .                         22505 

6. 

B! 

q 

21162 
24689 

2821fi 

8 

25720 

9.... 

..    .28935 

::  :§i743 

The  above  tables  render  the  conversion  of  the  weights  in  question  a  matter  of  great 
ease,  the  error  introduced  in  the  last  decimal  place  being  trivial. 

The  use  of  the  tables  will  be  best  illustrated  by  an  example.  Supposing  that  it  is  de- 
sired to  find  the  equivalent  in  grains  of  324.51  grams,  we  proceed  by  breaking  up  this 
number  into  the  following  series  of  constituent  parts,  and  finding  the  grain-equivalent  of 
each  part  from  the  table : 


Portions  of  original  number. 
800.00.... 


4.00 

.50 

.01.... 


Equivalents  in  grains. 

4630. 

308.6 

61.73 

7.716 

.1543 


5008.2003 


The  required  quantity  is  5008.2  grains.  The  numbers  taken  from  the  table  will,  in 
most  cases,  require  a  change  as  regards  the  position  of  the  decimal  point ;  thus,  to  find  the 
value  of  300  grams,  one  refers  to  the  table,  and  finds  46.30  given  as  the  equivalent,  and  a 
mere  shifting  of  the  decimal  point  two  places  towards  the  right  multiplies  this  by  100,  or 
gives  the  required  number.  In  a  similar  manner,  by  shifting  the  decimal  place  of  30.86  one 
place  to  the  right  we  obtain  the  value  in  grains  of  20  grams  ;  while  the  number  61.7  is  taken 
from  the  table  without  alteration  as  the  equivalent  of  4  grams.  For  .50  the  table  number 
must  have  its  point  shifted  on  to  the  left,  making  it  7.716  instead  of  77.16 ;  and  finally,  the 
value  of  .01  is  obtained  by  shifting  the  point  of  15.43  two  places  to  the  left. 

The  above  operations  are,  in  actual  practice,  performed  with  considerable  speed,  the 
required  equivalents  being  written  down  one  after  the  other  on  a  scrap  of  paper,  and  then 
added  up. 


THE   PROCESSES    OF    POKE    PHOTOGRAPHY. 


193 


TABLE  SHOWING  THE  COMPARISON  OF  THE  READINGS 
OF  THERMOMETERS. 


CELSIUS,  OR  CENTIGRADE  (C).     REAUMUR  (R).     FAHRENHEIT  (F). 


C. 

R. 

F. 

C. 

R. 

F. 

—30 

—24.0 

—22.0 

23 

18.4 

73.4 

—25 

—20.0 

—13.0 

24 

19.2 

75.2 

—20 

—16.0 

—  4.0 

25 

20.0 

77.0 

—15 

—12.0 

+  50. 

26 

20.8 

78.8 

—10 

—  8.0 

14.0 

27 

21.6 

80.6 

—  5 

—  4.0 

23.0 

28 

22.4 

82.4 

—  4 

—  3.2 

24.8 

29 

23  2 

84.2 

—  3 

—  2.4 

26.6 

30 

24.0 

86.0 

2 

—  1.6 

28.4 

31 

24.8 

87.8 

i 

—  0.8 

30.2 

32 

25.6 

89.6 

33 

26.4 

91.4 

Freezing  point  of  water. 

34 

27.2 

93.2 

35 

28.0 

95.0 

0 

0.0 

32.0 

36 

28.8 

96.8 

1 

0.8 

33.8 

37 

29.6 

98.6 

2 

1.6 

35.6 

38 

30.4 

100.4 

3 

2.4 

37.4 

39 

31.2 

102.2 

4 

3.2 

89.2 

40 

32.0 

104.0 

5 

4.0 

41.0 

41 

32.8 

105.8 

6 

4.8 

42.8 

42 

33.6 

107.6 

7 

5.6 

44.6 

43 

34.4 

109.4 

8 

6.4 

46.4 

44 

35.2 

111.2 

:         9 

7.2 

48.2 

45 

36.0 

113.0 

10 

8.0 

50.0 

50 

40.0 

122.0 

11 

8.8 

51.8 

55 

44.0 

131.0 

12 

9.6 

53.6 

60 

48.0 

140.0 

13 

10.4 

55.4 

65 

52.0 

149.0 

14 

11.2 

57.2 

70 

56.0 

158.0 

15 

12.0 

59.0 

75 

60.0 

167.0 

16 

12.8 

60.8 

80 

64  0 

176.0 

17 

13.6 

62.6 

85 

68.0 

185.0 

18 

14.4 

64.4 

90 

72.0 

194.0 

19 

15.2 

66.2 

95 

76.0 

203.0 

20 

16.0 

68.0 

100 

80.0 

212.0 

21 

16.8 

69.8 

22 

17.6 

71.6 

Boiling  point  of  water. 

Readings  on  one  scale  can  be  changed  into  another  by  the  following 
formulae,  in  which  /°  indicates  degrees  of  temperature: 


Reau.  to  Fahr. 

Cent,  to  Fahr. 

Fahr.  to  Cent. 

R  J  +  32°  =  t°  F 

?f°C  +  32°  =  f«  F 
o 

-  [  t°  F  —  32°  J=  / 

Reau.  to  Cent. 

Cent,  to  Reau. 

Fahr.  to  Reau. 

5 
4  /°  R  =  t°  C 

4 

F/°  C  =  t°  R 
o 

$(<•?-«)  =  ' 

194 


THE    PROCESSES    OF    PURE    PHOTOGRAPHY. 


ACKLAND'S   TABLES  FOR    THE    SIMPLIFICATION    OF 
EMULSION   CALCULATIONS. 


No.  1. 


Oc^ 

||| 

If 

&B£ 

a  'Sir10' 

111 

a  m 

IS 

•ts2^3 

III 

"o  E&3 

1-^^2 

11* 

&9 

•a  o* 

H!| 

mi 

Weight  o 
haloid  rei 
convert  o 
AgNOn. 

«       * 

f|8| 

£l£1 

isjl 

'S.x^'3: 

W*S 

y 

Ammonium  bromide  

98 

1.734 

.576 

1.918 

.521 

i 

Potassium                    

119.1 

1.427 

.700 

1.578 

.633 

Sodium                         

103 

1.650 

.606 

.825 

.548 

1  10fi 

Cadmium                    com.  .  . 

172 

.988 

1.012 

1.093 

.915 

•  1.  1UO 

"                  "        anh.  .  .  . 

136 

1.25 

.800 

.382 

.723 

Zinc                    "             ... 

112.1 

1.509 

.663 

1.670 

.600 

Ammonium  chloride. 

53.5 

3.177 

.315 

2.682 

Sodium                " 

58.5 

2.906 

.344 

2.453 

!408 

.844 

Ammonium  iodide.             .  . 

145 

1.172 

.853 

.617 

Potassium          " 

166.1 

1.023 

.977 

1.415 

.707 

Sodium               "     ......... 

150 

1.133 

.882 

1  566 

.638 

1.382 

Cadmium            "     . 

183 

.929 

1.076 

l'284 

.778 

Table  No.  1  presents  the  actual  weights  of  haloid  or  silver,  as  the  case 
may  be,  required  to  convert  or  combine  with  one  grain  of  another. 

In  order  to  make  (say)  ten  ounces  of  emulsion  by  a  new  formula, 
which,  for  the  sake  of  showing  the  working  of  the  table,  we  will  write 
down  as  follows  : 


Bromide  of  potassium 

Iodide  of  potassium 

Chloride  of  ammonium 

Gelatine 


150  grains. 

10        " 

...  10 


we  want  to  know  how  much  silver  nitrate  should  be  employed  in  sen- 
sitizing this  mixture.  For  this  purpose  we  use  the  first  column,  in  which 
we  find  against  each  haloid  the  exact  quantity  of  silver  nitrate  required  to 
fully  decompose  one  grain.  Taking,  then,  the  figures  we  find  in  column 
No.  1  against  the  three  salts  in  the  above  formula,  and  multiplying  them 
by  the  number  of  grains  of  each  used,  we  have  the  following  sum  : 


Potassium  bromide 

"          iodide 

Chloride  of  ammonium. . . 


150  X  1.4*<  =  214      )       Weight 

10  x  1-023  —   10.23  Vsilver  nitrate 

....  10  X  3.177  ;=    31.77 )      required. 


or  the  total  quantity  of   silver  nitrate  required  for  full  conversion,  256.00 
grains. 


THE    PROCESSES   OF    PURE    PHOTOGRAPHY. 


195 


'UNIFORM    SYSTEM"  NUMBERS   FOR  STOPS   FROM  /TO  T^ 

In  the  following  table  Mr.  S.  A.  Warburton  has  calculated  the  exposure 
necessary  with  every  stop  from  £  to  T^7  compared  with  the  unit  stop  of 
the  "uniform  system"  of  the  Photographic  Society  of  Great  Britain. 
The  figures  which  are  underlined  show  in  the  first  column  what  £  must 
be  in  order  to  increase  the  exposure  in  geometrical  ratio  from  £,  the 
intermediate  numbers  showing  the  uniform  system  number  for  any  other 
aperture. 


f 

1 

U.  S.  No. 

A 

f 
15 

U.  S.  No. 
14.06 

/ 

58 

U.  S.  No. 

210.25 

1M 

.097 

16 

16 

59 

217.56 

1.414 

k 

17 

18.06 

60 

225.00 

52 

i* 

.140 
.191 

V. 

18 
19 
20 
21 

20.25 
22.56 
25.00 
27  56 

62 
63 
64 

240.25 
248.06 
256 

a 

2.828 

.316 
.390 

^ 

22 
22.62 

30.25 
32 

65 
66 

264.06 
272.25 

F 

3^ 
894 

44 

.472 
.562 
.660 
.765 

.878 
1.00 

23 

24 
25 

26 

27 
28 

33.06 
36.00 
39.06 
42.25 
45.56 
49.00 

67 
68 
69 

70 
71 
72 
73 

280.56 
289.00 
297.56 
306.25 
315.06 
324.00 
333  06 

TO 

P 

1.12 
1.26 
1.41 
1.56 

30 
31 
32 

56.25 
60.06 
64 

74 
75 
76 

77 

342.25 
351.56 
361.00 
370  56 

5& 

5.656 

1.72 
1.89 

2 

33 
34 
35 

68.06 
72.25 
76.56 

78 
79 
80 

380.25 
390.06 
400.00 

5% 
6 

6K 
pi| 

6M 

7 

1 
$ 

2.06 
2.25 
2.44 
2.64 
2.84 
3.06 
3.28 
3.51 
3.75 
4 

36 
37 
38 
39 
40 
41 
42 
43 
44 
45 

81.00 
85.56 
90.25 
95.06 
.  100.00 
105.06 
110.25 
115.56 
121.00 
126.56 

81 
82 
83 
84 
85 
86 
87 
88 
89 
90 

410.06 
420.25 
430.56 
440.00 
451.56 
462.25 
473.06 
484.00 
495.06 
506.25 

8M 

4.25 

45.25 

128 

90.50 

512 

8^ 

F 

9^ 
9^ 
9% 
10 

11 

11.31 

4.51 
4.78 
5.06 
5.34 
5.64 
5.94 
6.25 
7.56 
8 

46 
47 
48 
49 
50 
51 
52 
53 
54 

132.25 
138.06 
144.00 
150.06 
156.25 
162.56 
169.00 
175.56 
182.25 

91 
92 
93 
94 
95 
96 
97 
98 
99 

517.56 
529.00 
540.56 
552.25 
564.06 
576.00 
588.06 
600.25 
612.56 

12 
13 
14 

y.oo 

10.56 
12.25 

55 
56 

57 

189.06 
196.00 
203.06 

100 

625.00 

196 


THE    PROCESSES    OF    PURE    PHOTOGRAPHY. 


O  <        I         oC*C.><™-^«>CO-*OO-*O'OWO-^«5«D«OOOt-Ot- 

H  -rH         I  -r-l.  «0    W  50    >»  t-^    t~  OO    <»  O»'   ??  O    35  ~    «?  C* 

B 

5 

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PERCENTAGE   OF  REAL   AMMONIA    IN     SOLUTIONS    OF 
DIFFERENT   DENSITIES  AT  14  DEG.  CENTIGRADE. 

(CARIUS.) 


Specific 
Gravity. 

Percentage 
Ammonia. 

Specific 
Gravity. 

Percentage 
Ammonia. 

Specific 
Gravity. 

Percentage 
Ammonia. 

Specific 
Gravity. 

Percentage 
Ammonia. 

0.8844 

36.0 

0.9052 

27.0 

0.9314 

18.0 

0.9631 

9.0 

0.8864 

35.0 

0.9078 

26.0 

0.9347 

17.0 

0.9670 

8.0 

0.8885 

34.0 

0.9106 

25.0 

0.9380 

16.0 

0.9709 

7.0 

0  8907 

33.0 

0.9133 

24  0 

0.9414 

15.0 

0.9749 

6.0 

0.8929 

32.0 

0.9162 

23.0 

0.9449 

14.0 

0.9790 

5.0 

0.8953 

31.0 

i  0.9191 

22.0 

0.9484 

13.0 

0.9831 

4.0 

0.8976 

30.0 

j  0.9221 

21.0 

0.9520 

12.0 

0.9873 

3.0 

0.9001 

29.0 

!  0.9251 

20.0 

0.9556 

11.0 

0.9915 

2.0 

0.9026 

28.0 

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19.0 

0.9593 

10.0 

0.9959 

200 


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INDEX. 


Abney,  Backing  for  Dry  Plates    49 
Abney,  Capt.,  Hydrochinon. ..     90 
Abney  at  Camera  Club  Confer- 
ence on  Orthochromatics. ...   113 
Abney  on  Orthochromatics. ...  112 

Absorption  of  Light- Rays 14 

Accelerator 84 

Acetate  Toning-Bath 128 

Actinometer  for  Carbon  Print- 
ing    158 

Albumen,     Combination     with 

Silver  Nitrate 121 

Albumen  Paper,    Flotation   on 

Silver  Bath   122 

Albumen  Prints,  Fixing 129  j 

Albumenized     Paper,    Prepar- 
ation of 121 

Albumenized    Paper,    Printing 

on 121 

Albumenized  Paper,   Silver  in.   121 

Albumenizing  Glass  Plates 37 

Alcohol,  Precipitation  of  Gela- 
tine by 62 

Alkaline  Developer  Discovered.     10 

Alkalis   as  Accelerators 84 

Alum  Bath,  Acid 97 

Alum  in  Gelatine  Emulsion...     68 
Ammonia,   Liq.  ft.,  sp.  gr.  of. .     85 

Ammonia,  Nature  of 84 

Ammonia,  Used  with  Dyes. . . .  Ill 
Ammonia  Sulphate  of  Iron....     42 

Ammonic  Carbonate 85 

Ammonio-Nitrate  Gelatine  Pro- 
cess       60 

Ammonio-Nitrate  Process. ..    .     10 

Apparatus 16  et seq. 

Architecture  with  Parallel  Lines    76 

Argus,  Finder 80 

Armstrong,  T.    N.,    Palladium 
TonerforWet-Collodion  Slides  781  ! 

Art,  Photography  an 7  | 

Atom 12 

Aurantia,  Yellow  Screen 113 

Autotype  Co.  Carbon   Printing  161   ! 

Backing,  To  Cure  Halation 103  j 

Backing  for  Dry  Collodion 49  j 

Bath,  for  Toning  and  Fixing. . .   140 

Bath,   Sensitizing 39 

Bath,  Silver 39 


Becquerel 11 

Beer  Process 10 

Bennett,  Charles 10 

Berkeley,    H.  B.,   His   Sulpho- 

pyrogallol  Solution    86 

Binocular  Vision 115 

Bitumen,  Action  of  Light  on  . .  8 

Bitumen  on  Metal  Plate 8 

Black  Cloth 27 

Blistering  of  Prints 131 

Blisters  on  Bromide  Prints 146 

Blocking-Out  Skies 135 

Boiled  Emulsion,  Gelatine    ...  59 

Boiling  Emulsion 10 

Bolton,  W.  B.,Dry  Collodion. .  46 

Borax  Toning-Bath 128 

Bothamley,  C.  H 11 

Bothamley,  Prof.  C.  H 112 

Bromide  Paper,  Brown  Tones.  146 
Bromide  Paper,  Washing  After 

Development 145 

Bromide  Papers,  Qualities  Sold  147 
Bromide    Prints,    Hydrochinon 

for 145 

Bromide  Prints,  Mounting  of.  .  147 

Bromide  Prints,  Washing 146 

Brooks.W.,  Developers  for  Dry- 
Collodion  Slides 175 

Burton,  H.J.,  Method  of  Sen- 
sitizing Carbon  Tissue 157 

Bye-Products      of      Decompo- 
sition   46 

Cabinet  Size 27 

Calcium  Tube,  to  Protect  Paper 

from  Damp 151 

Calotype,  Process 9 

Camera 16 

Camera,  Bellows ,  17 

Camera,  Landscape 17 

Camera,  Out-Door 17 

Camera,  Portrait 18 

Camera,  Stereo 115 

Camera,  Studio 17 

Camera,  Tapering 17 

Camera,    Test   for    Light-tight- 
ness    78 

Camera,  The,  in  the  Field 73 

Camera,  Tilting  the 75 

Camera,  Tourist , .  17 


Camera  Club  Conference,  1888  113 
Camera  for  Stereos,  Binocular.  116 
Camera      Photography      Intro- 
duced    8 

Camera  Stands 20 

Cameras,  Detective 79 

Cap  of  Lens,  Carrying 77 

Carbon  or  Pigment  Process. ...  156 
Carbon  Printing,  Safe  Edge  for  158 
Carbon  Printing  Process  and 

Swan 11 

Carbon  Prints,  Development  of  159 
Carbon  Process,  Defects  and 

Cures 163 

Carbon   Process   for    Lantern- 
Slides 162 

Carbon  Tissue,  Nature  of 156 

Carbon  Tissue,  Sensitizing 156 

Carbonate  of  Ammonia 85 

Carbonate  of  Potash 8 

Carbonate  of  Soda 85 

Carbutt,   Developer  for   Slides 

on  Gelatine  Bromide 178 

Carey,  Lea JO 

Carey  Lea's  Collocine 43 

Carrier,  or  Dark-Slide 16 

Carrier,  or  Dark-Slide 18 

Carrier,  or  Kit 19 

Carte  Size 27 

Centrifugal    Force,    Separation 

by 64 

Centrifugal  Machine 65 

Champney,   J.  W.,  His  Masks 

for  Slides 181 

Checkers,  Drop  or  Guillotine. .     24 

Citrates  in  Development 88 

Cleaning  Glass  Plates 36 

Clearing     Solution,      Gelatine 

Plates 97 

Cloth,  Black 27 

Cloud  Negatives,  To  Make 134 

Coating   Plates   with    Gelatine 

Emulsion 69 

Coating  with  Collodion 37 

Coating  with    Gelatine    Emul- 
sion, Arrangements  for 70 

Coffee,  Preservative,   Dry  Col- 
lodion        47 

Collocine 43 

Collodion,  Coating  with 37 

Collodion,  Future  of 36 

Collodion,  Iodized,  etc 36 

Collodion,   Wet  Negative  Pro 

Collodion  Bottle 36 

cess 36 

Collodion  Process,  Dry 46 

Collodion  Suggested  by  Le  Gray  9 
Collodion  Transfers 170 


Color,  Blue  ...................  12 

Color,  Violet  .................  12 

Color-Correct,  Photography....  11 

Color-Correct  Landscape,  Dan- 

ger of  Dark  Screen,  Foot  Note  113 

Color-Correct  Photography.  .  .  .  110 

Colors,  Orange  and  Red  .......  13 


Actinic 


Colors,     Visual     and 

Values 110 

Combination  Printing 134 

Condensers  for  Enlargement. .   164 
Contact  Printing,  Manipulation 

of 120 

Continuating  Action  of  Light. .   159 

Conversion  by  Ammonia 61 

Cowan,  A.,  Developer  for  Gela- 
tine-Chloride Plates 174 

Cowan's  Method  of  Dry  Mount- 
ing    132 

Cyanide  of  Potash 43 

Cyanine,  Solution  of,  in  Water.   112 
Daguerre,      Partnership     With 

Niepce 8 

Daguerreotype  Process 8 

Dark-Room,       Arrangements 

Hygienic 33 

Dark-Room    Light  for 30 

Dark-Room   Points  of 32 

Dark-Room 
Dark-Room 
Dark-Room 


Tap  for 
Temporary 
The. . . 


Dark-Room  Lamp 31 

Dark-Room  Sink 33 

Dark-Room s  for  Various   Pro- 
cesses      30 

Dark-Slide,  or  Carrier 16 

Dark-Slide,  or  Carrier 18 

Dark-Slide,  Partition  of 19 

Dark-Slide,  Shutter  of 19 

Dark-Slides,  Double 19 

Davey 8 

Davis',  T.    S.,  Method  of  Emu- 

sification 56 

Daylight    Enlargement,   Appa- 
ratus    166 

Defects  in  Albumen  Prints. . .  .   131 
Defects   in    Gelatine    Bromide 

Plates 100 

Defects  in  Stripping  Films 107 

Detective  Cameras 79 

Developer,  Alkaline,  Discovered  10 
84 
10 
81 
14 


Developer,  Alkaline  Pyro 

Developer,  Ferrous-Oxalate. . . 
Developer,  Ferrous  Oxalate. . . 
Development,  Definition  of.... 
Development,  Judging  Expo- 
sure by 


94 


INDEX. 


Development,      Manipulations 

for  Gelatine  Plates 92 

Development,  Slow  or  Tentative  89 

Development,  Time  of 88 

Development    Treated    Gener- 
ally   81 

Development,  Wet  Collodion.  .  41 
Development  for  Various  Sub- 
jects   89 

Development  of  Carbon  Prints.  159 
Development  of  Dry  Collodion 

Plates 48 

Development  of  Platinum  Prints  153 

Diaphragms  or  Stops 23 

Digestion  of  Emulsion 10 

Dipper  for  Dipping  Bath 40 

Dipping  Bath,  Silver  Solution.  40 

Dish  for  Development 28 

Dish  for  Toning 29 

Dishes,  Papier  Mach<§. 28 

Dishes,  Porcelain 29 

Distortion  of  Lines '. . . .  76 

Dodging  Negatives 133 

Double  Exposures,  to  Avoid..  78 

Double  Printing 134 

Double  Transfer  Carbon  Print- 
ing    161 

Drop  Shutter,  Aperture  of 25 

Dry-Collodion,  Emulsifying. ..  47 
Dry-Collodion,  Re-development 

for  Slides 177 

Dry-Collodion.  Unwashed...  46 

Dry-Collodion,  Washed.- 46 

Dry-Collodion  for  Slides,  Man- 
ipulation of 176 

Dry-Collodion  Plates,  Backing 

for 49 

Dry-Collodion  Process 46 

Dry-Collodion     Process,    Prin- 
ciples of 46 

Dry-Collodion  Slides 175 

Dry-Collodion  Slides,  Develop- 
ment   175 

Dry-Collodion   Slides,    to    Re- 
move Fog  or  Veil 177 

Drying,  Wet  Collodion  Plates.  44 

Drying  Albumen  Prints 131   | 

Drying  Closet 51 

Drying  Gelatine-Chloride  Prints  141 

Drying  Gelatine  Negatives. ...  97 

Drying  Gelatine  Plates 52 

Drying  Gelatine  Plates 71 

Drying     Marks     on      Gelatine 

Plates 72 

Drving  Paper  and   Film  Nega- 
tives    105 

Drying  Presses 51 

Drying  Rack 29 


Drying-Room 53 

Drying     Sensitized     Albumen 

Paper 125 

Dyes,  Action  of  in  Color-Cor- 
rect Photography 110 

Eastman  Co.,  Agents  or  Sepa- 
rator   65 

Eastman's  Paper  Negatives 104 

Eastman's  Roll-Holder 104 

Eder 11 

Eder   on  Orthochromatics 112 

Edwards,  B.  J.,  Developer  for 

Gelatine-Chloride  Plates 175 

Edwards,    B.    J.,    Hydrochinon 

Developer 145 

Emulsification      of      Gelatine- 

Chloro-Bromide 56 

Emulsification  for  Ammonio- 
Nitrate  Gelatine  Emulsion  . .  61 

Emulsion,  Dry  Collodion 47 

Emulsion,  Gelatine,  Apparatus 

for 53 

Emulsion,    Gelatine,    Effect    of 

Cooling  and  Setting 68 

Emulsion,    Ripening    of,    Dry 

Collodion 47 

Emulsion  Processes  Discovered 

by  Sayce  and  Bolton 10 

Enameling  Prints 132 

England's,  W.,    Dry  Press 53 

Enlarging  by  Optical  Lantern.    168 
Enlarging  Without   Condenser 

by  Daylight 165 

Enlargement,  Cheap  Apparatus  167 
Enlargement,  Dodging  During  168 

Enlargement,  Exposure 167 

Enlargement,  Heads  of 164 

Enlargement,  Illuminating  Ori- 
ginal  164 

Enlargement,  Optics  of 164 

Enlargement,     Projecting     the 

Image 164 

Enlargement,  The  Condenser.   164 
Enlargement,    The    Projecting 

Lens 167 

Enlargement,  The  Radiant 164 

Enlargements 164 

Enlargements,  Development  . .   168 

Eosine Ill 

Erythrosine   Ill 

Ether 12 

Exposure  and  Development  To- 
gether   82 

Exposure  for  Slides 174 

Exposure  of  Carbon  Tissue, 
Method  of  Judging  by  De- 
velopment   160 


INDEX. 


Exposure  of  Gelatine-Bromide 

Paper,  General  Remarks  on.  143 

Exposure  Treated  Generally. . .  81 

Exposure  with  Lens  Cap 27 

Exposure  with  Shutters 26 

Exposure  with  Stops 75 

Farmer,  E.  H.,  His  Reducer. . .  98 

Ferrous  Oxalate,  Bottle  for 92 

Ferrous  Oxalate  Developer. ...  91 
Ferrous  Oxalate  Developer,  Hy- 
po in  144 

Ferrous  Sulphate 42 

Field,  Camera  in  the 73 

Films,  Stripping 104 

Filter  Funnels 29 

Filtering  Gelatine  Emulsion. . .  70 

Finder,  Argus   80 

Finder,    Waterbury 80 

Finders 79 

Fining-Bath  for  Residues 183 

Fixing  Albumen  Prints 129 

Fixing  Albumen   Prints,  Time 

for 129 

Fixing  Gelatine  Plates 96 

Fixing  Image,  Early  Attempts. .  9 

Fixing  Wet  Plates 43 

Flap  Shutter 83 

Flotation   of  Albumen    Paper, 

Test  for  Time 122 

Flotation   of  Albumen   Paper, 

Time  Required 122 

Flux  for  Fusing  Residues 184 

Focal   Length,  Calculated  from 

Diagonal  of  Plate 23 

Focus,  Where  to,  in  Field 75 

Focus  of  Lens,  Remarks  on. . .  23 

Focusing  and  Finding 80 

Focusser  and  Finder,  J.  T.  Tay- 
lor's   80 

Fog,  Gray 101 

Fog,  Green.. 60 

Fog,  Green 100 

Fog,  Red 101 

Fog,  Red,  Elimination  of 67 

Fog,  Separated 101 

Fog  Due  to  Light 101 

Formulae,  Tables,  etc. ,  185  to  the  end 

Formulae  of  Plate  Makers 85 

Fox-Talbot 9 

Fox-Talbot,  His  First  Process.  9 

Frames,  Printing 119 

Frilling,  Causes  of 102 

Frilling,  Possible  Cure  for 97 

Frilling,  To  Prevent 94 

Gallic  Acid 9 

Gelatine,  a  Halogen  Absorbent  51 
Gelatine,    Chloride    Paper    for 

Certain  Negatives 140 


Gelatine,  Heinrich's  Hard 56 

Gelatine,  Nelson's  No.  1 55 

Gelatine,  Nelson's  X  Opaque. .     56 

Gelatine,  Properties  of 51 

Gelatine,  Quality  of,  for  Emul- 
sion       68 

Gelatine-Bromide  for  Slides. . .  179 
Gelatine- Bromide  Emulsion, 

Rapid,  by  Ammonio-Nitrate.     60 
Gelatine-Bromide      Emulsion, 
Rapid,  by  Boiling  Process. .     58 

Gelatine-Bromide  Opals 147 

Gelatine-Bromide  Paper 142 

Gelatine-Bromide    Paper,     De- 
scription of 142 

Gelatine-Bromide     Paper,    Ex- 
posure     143 

Gelatine-Bromide  Paper  Devel- 
opment  144 

Gelatine-Bromide  Printing,  Ad- 
vantages of 142 

Gelatine-Chloride    Paper,    Na- 
ture of 140 

Gelatine-Chloride  Printing 140 

Gelatine-Chloride    Slides,    De- 
velopers    174 

Gelatine-Chloro-Bromide  Emul- 
sion     , .     55 

Gelatine  Emulsion,  Discovered.  10 
Gelatine  Emulsion,  "Grain"  of  59 
Gelatine  Emulsion,  Tests  of 

Sensitiveness 59 

Gelatine  Emulsion,  Washing  of  57 
Gelatine  Emulsion  Filtering. .  70 
Gelatine  Emulsions,  Residues.  183 
Gelatine  Negatives,  Reduction 

of 98 

Gelatine  Pellicle  Made  by  Ken- 

nett 10 

Gelatine  Plates,  Drying 71 

Gelatine  Plates,  Fixing 96 

Gelatine  Plates,   Packing 72 

Gelatine  Plates,  Washing...  .  96 
Glass,  Cleaning  for  Gelatine 

Emulsion 69 

Goddard 9 

Gold  Terchloride 128 

Good   Technical  Negative,   De- 
finition....       81 

Grain  in  Strippers,   Cause  and 

Cure 107 

Grained    Surface     on     Carbon 

Prints 162 

Gray  Fog 101 

Green  Fog 60 

Green   Fog  85 

Ground-Glass,  Register  of 16 

Ground-Glass  in  Camera,  Use  of    16 


INDEX. 


Group  Lenses. 22 

Gun-Cotton 36 

Halation,  Causes,  &c.,  of 103 

Haloids  used  in  Gelatine  Emul- 
sion       51 

Hard  and  Thin  Negatives,  Print- 
Hardwich,  Formula  for   Sensi- 
tizing Plain  Paper 139 

ing 134 

Harrison,  W.  J.,  History  of  Pho- 
tography  , 11 

Henderson,    A.    L.'s,   Gelatine 

Emulsion  Washer 54 

Herschell,  Sir  J 9 

History  of  Photography 7 

History  of  Photography  by  Har- 
rison      11 

Holder  for  Plates,  Pneumatic. .     38 

Hydrochinon  Developer 90 

Hydrochinon  for  Bromide  Prints  145 

Hydrochinon  for  Slides 179 

Hypo  in  Ferrous  Oxalate 144 

Hypo  in  Prints,  Test  for 130 

Hyposulphite  of   Soda 44 

Instantaneous    Shots,    Finders 

and  Focusers  for 80 

Intensification,  Dry  Collodion.  49 
Intensification,  Wet  Process. . .  44 
Intensification  of  Wet  Plates 

with  Mercury 45 

Inten sifter.  Mercury  for   Gela- 
tine Plates 98 

Intensifying  Gelatine  Plates. . .     98 

Intensity  Ratio  of  Lens 23 

Interiors,  Photography  of 79 

Introduction 7 

Iodide  of  Starch,  Test  for  Hypo .  130 

Iodine  in  Silver  Bath 39 

Iron,  Ammonia  Sulphate  of...     42 

Iron  Proto-sulphate 42 

Ives 11 

Ives  on  Orthochromatics 112 

Ives  on  Orthochromatics 113 

Ives,  Processes  for  Color-Cor- 
rect Plates 114 

Jar,  Shut-over 53 

Kennett,  R 10 

Kit,  or  Carrier 19 

Lac  Varnish 44 

Lamp  for  Dark-Room 31 

Landscape,  Color-Correct 113 

Lantern     Enlarging,      Cheap 

Method 169 

Lantern-Slides     171 

Lantern-Slides,  Exposure 174 

Lantern-Slides,    Gelatine-Chlo- 
ride    174 

Lantern-Slides,  Masks  for....    181 


PAGE 

181 
172 
171 
180 


Lantern-Slides,  Mounting. . . 
Lantern-Slides,  Processes  for 
Lantern-Slides,  Qualities  of  . 
Lantern-Slides,  Scum  on.... 

Lantern-Slides,  Toning 177 

Lantern-Slides,  Uses  of 171 

Lantern-Slides  by  Carbon  Pro- 
cess    162 

Lantern-Slides  by  Reduction.. .   172 
Lantern-Slides  by  Transferotype  180 
Lantern-Slides  on  Gelatine-Bro- 
mide  178 

Lantern-Slides  on  Gelatine-Bro- 
mide—Warm Tones 179 

Le  Gray,  Suggests  Collodion  . .  9 
Leather  as  a  Basis  for  Silver  Salt  8 
Leather  Discs  for  Tripod  Feet  79 

Lens,  Focal  Length  of 21 

Lens,  Group 22 

Lens,  Intensity  Ratio  of 23 

Lens,  Portrait 21 

Lens,    Projecting,     for    Enlarge- 
ment  167 

Lens,  Rectilinear 22 

Lens,  Single 21 

Lens,  Special  Uses  of 21 

Lens,  Symmetrical 22- 

Lens,  Wide  Angle 22 

Lenses 21  et  seq. 

Lenses,  Rapid 22 

Lenses,  Twin,  for  Stereo 115 

Lens-Slits,  Leakage  of 79 

Leveling     Slab     for     Gelatine 

Plates 53 

Liesegang,    Dr.,   His   Gelatine- 
Chloride  Paper  and  Toner. .     140 

Light,  Chemical  Effect  of 13 

Light,  Continuating  Action  of.   159 

Light,  Heat-Rays  of 13 

Light,  Nature  of 12 

Light,  Visual  Effect  of 13 

Light,  Waves  of 12 

Light-Action,  Theory  of 12 

Light  Fog,  Test  for 101 

Light,  Refraction  of 12 


Ljght-tightness,  Testing  for 


Light-Waves,  Length  of. 

Light-Waves,  Pace  of 12 

Liver  of  Sulphur 183 

Local    Reduction    Gelatine 

Plates 99 

Maddox,  Dr.  R.  L 10 

Matt  Varnish,  Use  of 133 

Matter,  Constitution  of 12 

Mawsan  &  Swan's  Developer 
for  Slides  on  Gelatine-Bro- 
mide   179 

Measures,  Graduated 29 


Mercury    Intensifier,     Gelatine 

Plates 98 

M eta-bisulphite  of  Potash 87 

Microscopic  Test    of   Gelatine 

Emulsion 59 

Milan  Cathedral,    Photograph- 
ing on 79 

Molecule,  Definition  of 12 

Mounting  Albumen  Prints 131 

Mounting  Bromide  Prints 147 

Negatives,  Apparatus  for  Pro- 
ducing      16 

Negatives,  Paper 104 

Niepce,  and  Camera  Photogra- 
phy        8 

Niepce,  Death  of 8 

Non- Actinic  Lamp 31 

Note  Book  for  Exposures 78 

Obernetter,  Herr,  His  Gelatine- 
Chloride  Paper  and  Process.   141 
Oiling   Paper   Negatives,    Pro- 
test Against 105 

Optical  Contact,  Mounting  in. .  132 
Optical  Lantern  for  Enlarging.  168 
Optics  of  Photography ;  Their 

Uses 15 

Organic   Preservatives  and  Io- 
dine Absorbents 10 

Orthochromatic  Photography.  .   110 

Orthochromatics,  History 11 

Osmosis 102 

Over-density  of  Negative 101 

Packing  Gelatine  Plates 72 

Paper  Negatives 104 

Parallel  Lines  in  Architecture.     76 

Pellicle,  Dry  Collodion 48 

Permanent  Printing,  History. . .     11 

Permanent  Supports. . .    35 

Photographic  News,  Bothamley  112 
Photographic  Society  of  Great 

Britain,  Committee  on  Stops.     24 
Photography,     Orthochromatic 

or  Color-Correct 110 

Photography,  Stereoscopic 115 

Photography    An    Art    and    a 

Science 7 

Pigment  Printing,  History 11 

Pigment  Process  (Carbon) 156 

Pinholes 39 

Pizzighelli  and  Hiibl 150 

Pizzighelli's  Platinotype  Process  154 

Plain  Paper  Salting-Bath 137 

Plain  Salted  Paper,  Printing  on.  137 

Plate,  Half 27 

Plate,  Quarter 27 

Plate,  Whole 72 

Plate  Boxes 29 


Plates,   Coating  with   Gelatine 

Emulsion 69 

Plates,    Rinsed     with    Chrome 

Alum 69 

Plates,  Sizes  of 27 

Platinotype 150 

Platinotype,  Development 153 

Platinotype,  Negatives  for 155 

Platinotype,  Pizzighelli's  Process  154 

Platinotype,  Practice  of 151 

Platinotype,     Temperature     of 

Developing  Bath 154 

Platinotype,  Theory  of 151 

Platinotype  Company 150 

Platinotype  Paper,  Printing  of.  153 
Platinum  Paper,  Sepia  Tones  on  154 
Platinum  Printing,  Advantages 

of 150 

Platinum  Printing,  Defect  of. .  150 
Platinum  Salt  for  Platinotype. .  152 

Pneumatic  Holder ...     38 

Poitevin 11 

Positive  and  Negative 34 

Positive    First   Superseded    by 

Negative  Process 9 

Positive  for  Enlargement,  Quali- 
ties of 165 

Positive  Prints 118 

Potash,  Red  Prussiate  of 99 

Potassic  Bichromate,  Action  of.     10 

Potassic  Bisulphite 86 

Potassic  Bromide,  Adulteration 

of 55 

Potassic  Carbonate 85 

Potassic    Chloride,    Adultera- 
tion of 55 

Potassic  Cyanide 43 

Potassic  Cyanide,  Poisonous. .     44 

Potassic  Ferricyanide     99 

Potassic  Meta-Bisulphite 179 

Pouncey 11 

Pouton,  His  Discoveries 10 

Pouton,  Mungo 10 

Precipitation  of  Gelatine  by  Al- 
cohol       62 

Preparation  of  Silver  Bath 39 

Preservative,  Beer  and  Pyro. . .     47 

Preservative.  Coffee 47 

Preserving  Sensitive  Albumen 

Paper 125 

Print  Washing,  Water  for  Resi- 
dues    182 

Printing,  Permanent  Pigment. .  11 
Printing,  Platinotype,  History.  11 
Printing,  Various  Headings  of.  1.18 

Printing  Clouds 134 

Printing  Frame 118 

Printing  Frames,  Hinges  for. .  .   120 


Printing  Frames,  Registering. .  120 
Printing  in  Platinum  Salts..  . .  150 
Printing  on  Albumen  Paper.  .  .  116 
Printing  on  Gelatine  Bromide 

Paper 142 

Printing  on  Plain  Paper 137 

Printing  on  Rapid  Paper 148 

Printing  Room,  on  the 120 

Process,  Calotype 9 

Process,    Positive,   Superseded 

by  Negative 9 

Process,    Wet    Collodion    Ne- 
gative      36 

Pyro-Developer,  Alkaline 84 

Pyrogallol,  Effect  of  in  Develop- 
ment      85 

Pyroxyline,  High  Temperature     46 

Rack  for  Drying  Plates 29 

Rapid  Printing  Paper 148 

Rapid  Printing  Paper,  Develop- 
ment. ..'. 148 

Rapid  Printing  Paper, Toning  of  149 

Rays,  Visible,  of  Light 12 

Reade,  Rev.  J.  B 9 

Re-development,  Dry  Collodion  49 
Re-development,  Wet  Process..  43 

Red  Fog 101 

Red  Fog,  Elimination  of 67 

Reduction,  Apparatus  for 172 

Reduction,  Local,    Gelatine 

Plates 99 

Reduction,  Photo-Chemical 15 

Reduction  of  Gelatine  Plates. .  98 
Reflection  and  Transmission  of 

Light 14 

Refraction 12 

Register  of  Ground-Glass 16 

Residues,  Chloride,  Treatment 

of 183 

Residues,  Collodion  Emulsion.  183 
Residues,    Estimation    by    Re- 
finer   184 

Residues,  Gelatine  Emulsions.  183 
Residues,  General  Remarks...  182 
Residues,  Hypo,  Treatment  of.  183 
Residues.  Old  Toning-Baths. ..  183 

Residues,  Paper 182 

Residues,  Platinum •  184 

Residues,  Sulphides 183 

Residues,  to  Fuse  184 

Residues,  Wash  Waters 182 

Restrainer 84 

Reversing  Back  in  Cameras. . .     17 

Ritter 8 

Robinson,  R.  W.,  on  Green  Fog  101 

Roll-Holder,  Eastman's 104 

Roll-Holders,  When  to  Roll..     78 


Room     for     Drying     Gelatine 

Plates 53 

Rose  Benzol HI 

Safe  Edge  for  Carbon  Printing.  158 
Salt   Bath   for    Gelatine  Nega- 
tives      97 

Salting    and    Sizing    for    Plain 

Paper 173 

Sayce,  B.  J.    and  Bolton.W.  B.     10 

Scales  and  Weights 29 

Scholzig,  W.  O.,  His  Size 138 

Schumann 11 

Schumann  on  Orthochromatics  112 

Science,  Photography  a 7 

Scott-Archer,     First    Collodion 

Process 9 

Screen,  for  Color-Correct  Land- 
scape    113 

Screen,  Yellow,  Aurantia  for. .   113 
Screen,  Yellow,  for  Orthochro- 
matics    112 

Screens  for  Color-Correct  Pho- 
tography, Use  of 110 

Scum  on  Slides,  To  Remove ...   180 

Seebeck 8 

Seed  Lac  Varnish 44 

Senier,  H.;   Process  for  Warm 

Tones  in  Bromide  Prints 147 

Sensit  ve  Material,  Definition  of.  14 
Sensit  ve  Plates,  Box  for  Storing  29 
Sensit  zing  Albumen  Paper, 

Manipulations  of 124 

Sensit  zing  Bath,  Wet  Collodion     39 
Sensit  zing  Carbon  Tissue,  Ap- 
paratus for 157 

Sensitizing  Carbon  Tissue  from 

Back 157 

Sensitizing  Plain  Paper 139 

Sensitizing  Platinotype  Paper..  152 
Sensitizing  the  Plate,  Wet 

Process 40 

Separation      by      Centrifugal, 

Force,  Principles  of 64 

Separation  of  Gelatine  by  Cen- 
trifugal Force 64 

Separator,  Agents  for 65 

Separator,  Drum  of.  Size 65 

Sepia  or  Brown  Tones  on  Bro- 
mide Paper 146 

Setting,      Time    Required    for 

Plates 71 

Shut-over  Jars 53 

Shutter,  Cut-Off 19 

Shutter,  Duplex 25 

Shutter,  Stop  and  Hinge 19 

Shutter  Flap,  Use  of 83 

Shutter  of  Dark-Slide 19 

Shutter  of  Slide,  American 78 


INDEX. 


PAGE 

Shutters,  Points  of 25 

Shutters  for  Instantaneous  Work    24 
Sienna,  Powdered,  for  Backing.     94 
Sieve,  Hair,  for  Gelatine  Emul- 
sion       54 

Silver,  Iodide  of,  Niepce 9 

Silver  Bath,  Failures  with 40 

Silver  Bath,  Receptacles  for. . .     40 

Silver  Bath,  Strength  of 39 

Silver  Bath  for  Albumen,  to  De- 
colorize   123 

Silver  Bath  for  Albumen  Paper  122 
Silver  Bath  for  Albumen  Paper 

Test  for  Strength   123 

Silver  Bromide,  Goddard 9 

Silver     Bromide     in     Gelatine 

Emulsion 51 

Silver  Chloride,  Action  of  Light 

on,  First  Noticed 8 

Silver  Nitrate,  Converted 61 

Silver   Printing    on   Albumen, 

Sensitizing  Bath  for 121 

Single  Lenses,  Qualities  of. ...     22 
Single  Transfer,  Carbon  Print- 
ing    160 

Sink  for  Dark-Room 33 

Sizes  of  Plates 27 

Skin  for  Stripping  Films 107 

Sky,  Blocking  Out 135 

Slab      for     Leveling    Gelatine 

Plates 53 

SlidesbyWet-Collodion,Toning  178 
Sliding  Legs,  Advantages  of . .     79 
Sodic,    Tungstate,    and    Phos- 
phate Toning- Bath 139 

Sodic  Carbonate 85 

Sodic  Hypo-sulphite 44 

Sodic  Hyposulphite  and   Hers- 

chell   9 

Sodic  Sulphite  Intensifier  ...     98 

Solutions,  Ten  per  cent 86 

Specific  Gravity  of  Ammonia.  . .     85 

Spectroscope 14 

Spectrum 15 

Spots  on  Gelatine  Negatives. . .   102 

Stand,  Tripod 21 

Stand,  Studio 20 

Stands  for  Cameras 20 

Starch  for  Mounting 131 

Stereo-Plate,   Size  of 115 

Stereo-Prints,  to  Mount 117 

Stereoscope,  Reflecting. .......   116 

Stereoscope,  Refracting 116 

Stereoscopic  Photography 115 

Stop,  Rotating  24 

Stops,  Usual  Sizes  of 24 

Stop,  What  to  Use 75 

Stops,  Mode  of  Carrying 77  ' 


Stops — or  Diaphragms 23 

Stripping  Films 104 

Stripping  Films.  Developer  for  106 
Stripping  Films,  Manipulations  106 
Stripping  Films,  Other  Than 

Eastman's 108 

Supports 34 

Supports,  Permanent 35 

Supports,  Temporary 35 

Swan 11 

Swan's-down  Calico,  Filtering  70 

Swingback,  in  Cameras 17 

Swingback,  Uses  of 76 

Tables  of  Exposure,  Remarks 

on..  81 

Tap  for  Dark-Room 33 

Taylor.  J.  T.,  Supplementary 

Lens  for  Lantern  Enlarging.  169 

Taylor  on  Stereo  Sizes 116 

Temporary  Supports 35 

Terchloride  of  Gold 128 

Test  for  Light  Fog 101 

Thinness  of  Negative 102 

Thymol,  Antiseptic  for  Gela- 
tine Emulsion 58 

Tilting  the  Camera 75 

Toddy  Ladle  for  Gelatine 

Emulsion 70 

Toning,  Dish  for 128 

Toning,  Washing  Before 127 

Toning  Albumen  Prints,  Theory  126 

Toning  and  Fixing-Bath 140 

Toning  Dish 29 

Toning  Sensitive  Albumen 

Paper 125 

Toning  Slides  With  Platinum. .  177 
Toning  Solution  for  Plain  Paper  139 

Toning- Bath,  Borax 128 

Toning-Bath,  Old  for  Residues.  183 
Toning-Bath,  Sodic  Acetate...  128 
Toning  Bath,  Temperature  ...  128 

Transferotype,  Eastman's 147 

Transferotype  for  Slides 180 

Transfers  on  Collodion 170 

Translucine 105 

Transmission  and  Reflection  of 

Light 14 

Transparent  Positives,  Wet 

Process 44 

Tripod,  to  Prevent  Slipping..  79 

Tripod,  to  Use  Erect 74 

Tripod  Feet,  Discs  for 79 

Tripod  Stands,  Points  of 21 

Tunny,  an  Iron  Developer 9 

Tunny,  J.  G 9 

Twin  Lenses 115 

Uniform  System 24 

Varnish,  Negative,  to  Apply. . .  44 


INDEX. 


Varnish     for    Wet     Collodion 

Plates 44 

Varnishing  Gelatine  Plates 97 

Vehicle  and  Support 34 

Vehicles...  34 

Vergara  Films 109 

View  Meters 79 

Vignetting 136 

Vignetting  in  Enlargement ....  168 

Vision,  Binocular 115 

Vogel 11 

Vogel  on  Orthochromatics 112 

Vulcanite  Sheet 105 

Warnerke,  Toning  and  Fixing 

Rapid  Paper 149 

Warnerke's  Sensitometer 

Screen 158 

Washing  Albumen  Paper  Before 

Toning 127 

Washing  Albumen  Prints 130 

Washing  Albumen  Prints,  Ma- 

chine  for 130 

Washing  Bromide  Prints 146 

Washing  Gelatine  Emulsion. ..  57 
Water,  to  Purify  Silver  Bath. . .  39 
Water  for  Silver  Bath 39 


Waterbury,  Finder 80 

Watson,   Laidlaw  &  Co.,  their 

Centrifugal  Separator 65 

Wave-Lengths,  of  Light,  Theo- 
ries of 13 

Waves,  Length  of  Light 12 

Waxing  Solution,  Carbon  Pro- 
cess    161 

Webster,  G.  W.,  on  Citrates. . .     88 

Wedgewood 8 

Wellington,  J.    B.,    on   Ortho- 
chromatics 112 

Wet  Collodion  Process 36 

Wet  Collodion  Process,   Devel- 
opment      42 

Wet  Collodion  Slides 178 

Wet  Process,  Theory  of 36 

Wide-Angle  Lens,  Meaning  of.     22 

Willis,  W 10 

Willis,  W.,  and  Platinotype. ...     11 

Willis,  W.,  Platinotype 150 

Wilson,   G.  W.,   Mountant  for 

Slides 189 

Yellow  Stain  on  Gelatine  Neg- 
atives   102 

Zinc  Bromide 46 


LEWIS  MILLER.  JOHN  H.  VINCENT. 

PRESIDENT.  CHANCELLOR. 

K.    F.    KIMBALL,   BUFFALO,   N.   Y.,   Scc'Y   C.  S     P. 


Ghautanqua  School  of  Photography, 


MOTTO:       AND  THERE   WAS   LIGHT.' 


' ....  Class  of  1890 to 


Member's    c 

Class  &{o 

Tost  Office  Address,.. 
County, 


State, ^^d^«^^:j^^- 


IN  ADDRESS  SHOULD  BE  REPORTED  WITHOUT  DELAY  TO  THE  SCHOOL 
HEADQUARTERS. 


SCHOOL  HEADQUARTERS 

423  Broom<?  5tn^t,     - 


Cbarlce  Ebrmann/ 

INSTRUCTOR. 


TO    THE  MEMBERS 

of  the 

CHAUTAUQUA   SCHOOL  OF  PHOTOGRAPHY 

ON  JOINING   THE  CLASS. 


It  is  my  agreeable  duty  to  welcome  you  to  mem- 
bership in  our  class  for  the  study  of  Photography,  and  to  advise  you  that 
your  name  has  been  entered  upon  the  books  of  the  Chautauqua  University. 
The  payment  of  your  fee  for  the  full  course  of  one  year,  is  hereby  acknowl- 
edged, and  you  have  been  enrolled  upon  the  list  at  the  headquarters  of  the 
C.  S.  of  P. 

A  meeting  of  all  members  and  ex-members  of  the  school,  graduates 
and  undergraduates,  will  take  place  annually,  immediately  after  the  Recog- 
nition Day  of  the  Chautauqua  Literary  and  Scientific  Circle,  when  Diplomas 
will  be  presented  to  the  graduates  of  the  school,  premiums  awarded  to 
successful  competitors,  and  discourses  be  held  on  photographic  topics. 

You  are  cordially  invited  to  be  present  at  all  such  occasions. 

Trusting  that  you  will  enter  into  the  school  lessons  with  enthusiasm 
and  in  case  of  any  perplexities,  you   will   not  hesitate  to  make  use  of  the 
question  box;  also,  that   yon  will  join    with    me  in  faithfully   attending  to 
the  reading  and   practice  in   the  order   indicated   by  our  programme,  and 
that  you  will  be  one  of  the  successful   candidates  for  a  diploma  at  Chau- 
tauqua, in... ..y.^.P^..... .     I  am, 

Sincerely  your  friend, 


The  Chautauqua  School  of  Photography  instructs  in  four  classes, 
(l)  The  Corresponding  Class.  (2)  The  Practicing  Class  at  the  Assembly 
Ground.  (3)  The  Local  Class  at  the  School  Headquarters,  423  Broome 
Street,  New  York.  (4)  The  Post-graduate  Course. 

Every  member  of  the  Corresponding  Class  must  read  during  the  week 
the  lesson  which  is  sent  by  mail,  and  the  answers  to  queries  in  the  weekly 
PHOTOGRAPHIC  TIMES,  as  well  as  everything  else  published  there  of  interest 
to  members  of  the  C.  S.  of  P. 

After  the  expiration  of  the  first  term,  which  ends  with  the  twenty- 
fourth  weekly  lesson,  scholars  are  required  to  study  during  the  rest  of  the 
year,  "  The  Process  of  Pure  Photography,"  by\V.  K.  Burton  and  Andrew 
Pringle. 

If  there  is  anything  that  you  do  not  understand  in  the  lessons  after  you 
have  read  them  carefully,  please  report  your  difficulty  at  once  to  the  Question 
Box. 

Members  are  requested  to  communicate  frequently  with  the  Instructor, 
to  ask  for  information  when  needed  and  to  present  occasionally  specimens  of 
their  work  which  will  be  duly  criticised  in  the  organ  of  the  school. 

At  the  expiration  of  the  yearly  course,  examination  papers  will  be  sent 
to  each  member.  The  answers  are  to  be  filled  in  and  the  papers  returned  to 
headquarters  at  the  time  designated,  accompanied  by  three  finished  photo- 
graphs. All  who  answer  80  per  cent,  of  the  questions  correctly,  if  their 
required  work  has  also  been  done,  will  receive  a  diploma  from  the  Chau- 
tauqua School  of  Photography  on  graduation  day. 

Any  member  who  fails  to  pass  the  examination,  and  who  wishes  to  try 
again,  can  do  so  by  making  application  for  a  special  examination,  and  will  be 
expected  to  answer  90  per  cent,  of  the  second  series  of  questions. 

In  the  Practicing  Class  at  the  Assembly  Grounds  and  the.  Local  Class 
at  New  York,  exercises  in  studies  and  field  will  be  had,  and  instruction  given 
in  photographic  theories,  the  preparation  of  photographic  chemicals,  and  in 
such  special  branches  as  may  be  within  the  reach  of  the  Institute.  Scholars 
of  these  two  classes  will  be  admitted  to  examination  and  can  compete  for 
Diplomas  or  Premiums,  if  they  have  followed  the  reading  of  the  Corre- 
sponding Class. 

The  students  of  the  Post-graduate  Class  are  instructed  by  the  pre- 
scribed reading,  and  by  special  correspondence  with  the  Instructor. 

The  course  will  last  two  years  and  comprises  instruction  in  Chemistry, 
Photographic  Theories,  Optics  and  Aesthetics. 

Examination  every  six  months.  From  the  general  average  of  all  the 
questions  answered,  the  merits  of  the  students  will  be  determined.  When  80 
per  cent,  have  been  correctly  answered,  the  student  is  entitled  to  the 
Advanced  Diploma  of  the  Chautauqua  School  of  Photography. 


RyleS  f®p  Mddpessing  fehe  Question  B©x. 

i. — Address  all  letters  to  the  PHOTOGRAPHIC  TIMES'  QUESTION  Box, 
423  Broome  Street,  New  York  City,  giving  your  full  name  and  class  number. 

2. — Write  only  on  one  side  of  the  paper,  and  put  each  question  on  a 
separate  slip  of  paper ;  sign  every  slip,  and  put  on  each  your  class  number. 

3. — Write  plainly,  briefly,  and  to  the  point.  If  you  wish  to  study 
any  particular  branch  of  Photography,  report  names  of  books  already  read, 
and  ask  for  names  of  others. 

4. — Questions  will  be  answered  only  for  those  whose  record  at  school 
headquarters  shows  them  to  be  active  working  members. 

5. — Do  not  ask  for  employment  or  advice  about  business,  as  this  is 
beyond  the  school  work. 


Rules  f©i?  S©veP^in    MnSwei?S. 


1.  —  Questions  will   be   answered  in  the  order  of  reception  as  far  as 
possible  to  do  so. 

2.  —  All  answers  will  be  communicated  through  the  Chautauqua  Sup- 
plement to  the  monthly  PHOTOGRAPHIC  TIMES  and  the  class  number  will 
be  placed  opposite  the  reply. 


and  Sfehep  Requisites. 

Besides  the  prescribed  reading,  students  are  advised  to  read, 
No.  28.      THE  AMERICAN  ANNUAL  OF  PHOTOGRAPHY  AND  PHOTO- 
GRAPHIC TIMES  ALMANAC.      Finely   illustrated.     Paper;   (by 

mail,  12  cents  additional) , $o  50 

Library  Edition,  (by  mail,  1 2  cents  additional) I  oo 

No.  30.  PICTORIAL  EFFECT  IN  PHOTOGRAPHY.  By  H.  P.  ROBIN- 
SON. A  new  edition.  Illustrated.  Mr.  Robinson's  first  and 
best  work.  Cloth  bound i  50 

No.  31.  A  DICTIONARY  OF  PHOTOGRAPHY.  For  the  Professional 
and  Amateur  Photographer.  By  E.  J.  WALL.  Illustrated. 
240  pages.  Cloth  bound I  50 

Books  and   Photographic    Requisites   may   be   obtained    through   the 
Instructor. 


CHAUTAUQUA  UNIVERSITY. 

LEWIS  MILLER,  PRESIDENT. 
J.  H.  VINCENT,  CHANCELLOR.  R.  S.  HtlLMES,  REGISTRAR. 


THE 


Ciljaiifeaiiqiia  {Scjjool  of  photograph}, 

SCHOOL    HEADQUARTERS, 

423  BROOME  STREET,  NEW  YORK. 


CHARLES     WAGER     HULL, 

Supt.  of  Instruction,  C.  S.  of  P. 


INTRODUCTORY. 


THE  series  of  articles,  or,  perhaps,  more  properly  speaking, 
lessons,  which  it  is  proposed  shall  follow  this,  are  written  more 
especially  for  those  who  know  little  or  nothing  of  the  charming 
art  of  photography,  yet  desire  to  be  taught  its  mysteries  by  easy, 
simple  methods,  leaving  for  later  study  the  whys  and  the  where- 
fores, the  chemistry  and  the  science.  My  experience  has  proven 
that  the  amateur  or  the  beginner  is  far  too  much  inclined  to  ask 
questions  that  later  on  would  be  well  and  proper,  too  apt  to  be- 
come an  experimenter  while  yet  a  tyro,  too  apt  to  fill  his  note- 
book and  his  head  with  conflicting  theories  and  formulas,  not 
patient  enough  when  under  simple  instruction,  too  anxious  to  do 
everything  at  once;  these  rarely  succeed;  success  attends  those 
who  move  only  as  fast  as  they  learn,  and  understand. 

To  become  even  moderately  successful,  photography  demands 
of  its  votaries  certain  characteristics,  a  few  of  which  it  is  proper 
the  beginner  should  know  of  and  appreciate;  upon  them  success 
depends. 

PATIENCE,  for  photography  being  based  upon  chemical 
conditions  and  changes,  moves  only  just  so  fast,  it  cannot  be  hur- 


ried.  You  cannot  make  a  better  picture  by  using  a  stronger 
developer,  thus  gaining  time,  by  "hurrying  things  up;"  it  is  not 
like  driving  a  nail  or  sawing  a  stick  of  wood.  Patience  to  wait 
for  the  right  time  of  day  and  the  right  sort  of  light;  patience  to 
look  your  subject  all  over,  study  it,  find  the  most  pleasing  point 
•of  view;  the  resulting  picture  will  then  satisfy  you,  your  labor  has 
been  rewarded.  The  writer  knows  quite  a  number  of  amateurs 
who  should  have  painted  on  their  cameras,  "  Wholesale  only." 
They  don't  care  half  as  much  for  quality  as  they  do  for  quantity; 
they  can  make  more  pictures  in  a  day  than  a  painstaking,  good 
working  man  can  make  in  a  week,  but  not  one  in  a  dozen  is 
worth  the  cost  of  the  soda  contained  in  the  developer. 

This  kind  of  photographer  reminds  one  of  the  boy  who  busies 
himself  on  the  Fourth  of  July  by  blazing  away  from  a  revolver, 
and  measures  his  patriotism  by  the  number  of  shots  fired. 
This  kind  of  chap  never  makes  a  good  photographer. 

ORDER. — This  is  an  absolute  requirement.  When  it 
is  understood  that  each  chemical  is  used  to  produce  a  certain 
condition,  when  brought  into  relation  with  another  chemical, 
it  is  obvious  that  the  bringing  together  of  chemicals  at  the 
wrong  time,  or  in  the  wnong  order,  must  destroy  the  work  in 
hand.  If,  as  is  constantly  the  case,  various  operations  are  going 
along  at  the  same  time,  the  greatest  care  must  be  used,  by  con- 
tinually wiping  the  fingers,  that  those  solutions  which  should  be 
kept  apart  are  so  kept.  Faith,  not  only  in  your  teacher,  but  in 
your  own  efforts  as  well,  is  essential  to  success  ;  not  that  the 
methods  of  instruction  or  the  fprmula  to  be  given  are  any  better 
than  others  ;  but  that  they  will  enable  the  student  to  make  as 
good  a  photograph  as  the  writer  can  make,  which,  the  writer  flat- 
ters himself,  will  fully  satisfy  the  student. 

Follow  closely  and  exactly  everything  that  you  are  instructed 
to  do;  under  no  circumstances  adopt  or  attempt  changes;  when 
all  has  been  done  as  directed,  the  course  finished,  and  good  work 
made,  then,  and  not  until  then,  plunge  into  the  boundless  field  of 
theory  and  experiment,  and  good  may  then  come  of  it. 

Those  who  think  they  know  it  all,  or  know  somebody  who 
does;  who  are  not  willing  to  follow  as  herein  to  be  directed,  will 

3 


not  do  justice  either  to  themselves  or  to  the  teacher.  Last  and 
by  no  means  the  least  important  requirement  is  that  those  who 
propose  to  learn  the  art  of  photography  must  love  it,  be  patient 
and  persevering  ;  getting  tired  and  saying  "  I  guess  that'll  do," 
will  never  make  a  good  picture.  Now,  a  word  or  two  as  to  the 
benefits  to  be  derived. 

BENEFITS.— Hidden  here  and  there  along  every  road- 
side, every  hill-side  stream,  every  woodland,  everywhere,  indeed, 
are  beauties  not  seen  by  the  uneducated  eye;  but  pick  up  your 
camera  on  a  fine  bright  morning,  leisurely  stroll  along,  and  you 
will  find  new  beauties  each  time;  the  more  familiar  you  become 
with  nature's  beauties,  the  more  familiar  nature  will  become  with 
you;  you  see  what  you  never  saw  before,  for  the  reason,  you 
never  observed,  you  never  searched  for  her  beauties  ;  now  that 
you  know  them,  of  them,  you  will  never  find  the  end.  Pages 
might  be  written  on  this  benefit  alone  ;  it  is  worth  far  more  than 
it  will  cost  to  acquire  it. 

Another  of  the  chief  charms  of  photography  is  its  unselfish- 
ness; the  pictures  made  on  a  morning  ramble  are  not  alone 
enjoyed  by  the  maker,  but  enjoyed  as  well  by  all  his  friends. 
This  cannot  be  said  of  the  ordinary  pastimes  of  our  day. 

In  closing  this  rather  long  Introductory,  the  writer  desires  to 
impress  upon  students  the  fact,  that  he  considers  its  maxims  quite 
as  important  as  any  directions  which  follow. 


CHAUTAUQUA  UNIVERSITY. 

LEWIS  MILLER,  PRESIDENT. 
J.  H.  VINCENT,  CHANCELLOR.  R.  S.  HOLMES,  REGISTRAR. 


THE 


fljautouqua  j&jool  of 

SCHOOL    HEADQUA 

423  Broome  Street,  New  York 


CHARLES     WAGER     HULL, 

Supt.  of  Instruction,  C.  S.  of  P. 


LESSON  No.  I. 


APPARATUS  AND   REQUISITES. 

IN  photography,  as  in  all  other  industrial  pursuits,  certain  ap- 
paratus or  tools,  so  to  speak,  are  needed  to  produce  a  picture; 
some  you  can  buy,  others  with  but  little  labor  and  ingenuity  you 
can  make.  This  lesson  is  written  to  inform  you  of  those  you 
must  have,  and  leave  to  your  own  judgment  the  purchase  of 
those  which,  though  not  absolutely  necessary,  are,  nevertheless, 
of  considerable  comfort  in  carrying  forward  the  various  opera- 
tions through  which  you  are  to  be  led. 

The  first  group  of  essentials  will  be  the  camera  and  plate- 
holder,  the  lens,  the  tripod,  the  cloth  to  be  used  when  examining 
the  image  cast  upon  the  ground  glass  by  the  lens,  and  the  focus- 
ing-glass. 

Cameras  vary  greatly  in  their  design,  and  in  the  means  adopted 
to  produce  certain  necessary  conditions.  They  should  be  as 
light  as  is  consistent  with  the  work  they  have  to  do,  but  not  so 
light  as  to  be  liable  to  injury  from  the  accidental  blows  they  are 
almost  certain  to  receive  in  out-door  work. 

Cost  is  too  often  held  to  be  the  first  consideration  ;  good 
workmanship  and  simplicity  is,  in  the  writer's  opinion,  of  greater 
value  to  the  amateur  than  the  few  dollars  difference  in  price. 


For  all   uses   for  which   they  are    intended,  the  "  Favorite "   or 
"  Waterbury  "  cameras  meet  every  requirement. 


The  first-named  of  these  cameras  is  made  of  light  walnut,  and 
the  latter  of  mahogany.  They  have  rubber  bellows;  folding  plat- 
form, single  swing,  vertical  shifting  front,  record  slides  and  side 
latch  for  holding  platform  rigid.  /  The  two  features  last  named 
are  especially  desirable;  they  are  as  light  and  compact  as  sub- 
stantial cameras  can  be  constructed.  The  sizes  made  of  this 
style  are  for  pictures  4  inches  by  5  inches;  5  inches  by  8  inches, 
and  6£  inches  by  8£  inches.  These,  with  rare  exceptions,  are  the 
sizes  used  by  amateurs. 

To  those  readers  who  do  not  know  anything  about  cameras,  it 
is  well  to  explain  certain  parts  named,  and  their  uses.  The  rubber 
bellows  is  that  part  between  the  front  and  back  of  camera,  made  to 
allow  them  to  be  moved  together  or  apart  as  may  be  required  in 
adjusting  the  focus,  or  the  making  sharp  and  distinct  of  the  image 
on  the  ground  glass.  The  ground  glass  is  that  part  which  in  cut 
is  represented  as  falling  back,  in  the  place  of  which,  as  will  be 
described  later  on,  the  holder  containing  sensitive  plate  is  placed. 

The  single  swing  is  that  part  of  the  camera  to  which  the  ground 
glass  is  attached  on  left  or  back  part  of  the  cut;  it  is  an  adjust- 
able arrangement  held  in  place  by  a  thumb-screw,  as  shown,  and 
may  be  tilted,  as  shown  in  the  cut,  to  the  front  or  to  the  rear,  or 
may  be  placed  vertical.  Its  uses  are  many;  it  serves  to  equalize 
the  focus;  by  proper  use  the  foreground  containing  the  near  ob- 
jects in  a  picture  is  made  clear  and  distinct,  or,  as  photographers 
say,  "sharp." 

Vertical  shifting  front  is  that  part  on  which  the  word  "  Scovill  " 
is  seen;  it  may  be  elevated  or  lowered  at  will,  and  is  held  firmly 


in  place  by  a  thumb-screw.  On  this  front  the  lens  is  placed;  by 
lowering  it  more  foreground  is  brought  into  the  picture;  by  ele- 
vating or  raising,  less  foreground. 

Side-latch  for  holding  platform  rigid,  is  the  bolt  seen  on  tne 
platform  or  bed-piece,  and  holds  rigidly  the  folding  platform. 

The  folding  platform  folds  up  against  the  back  of  the  camera, 
when  the  back  has  been  pushed  forward  until  it  meets  the  front. 

This  simple  and  effective  arrangement  not  alone  renders  the 
camera  more  portable,  by  reducing  its  size,  but  as  well  protects 
the  bellows  from  injury  during  transportation. 

One  of  the  most  important  factors  in  the  production  of  the 
photographic  picture  is  the  lens,  of  which,  like  the  camera,  there 
is  an  endless  variety.  Fortunately  for  the  beginner  of  limited 
means,  the  improvement  in  lenses  places  within  the  reach  of  all 
good  lenses  for  very  little  money.  Nothing  can  surpass  for  all 
the  ordinary  views  of  still  life  the  "  Waterbury "  lens.  It  is 
moderate  in  price,  and  for  purpose  stated,  meets  every  require- 
ment. It  has  good  depth  of  focus,  by  which  is  meant  objects 
near  by  and  distant  are  both  clearly  denned;  covers  a  good  field, 
or  breadth  of  subject,  and  works  with  fair  rapidity. 


THE  WATERBURY  LENS  AND  DTAPHRAGMS 

With  it  most  excellent  landscapes  and  groups  can  be  made  in  a 
very  few  seconds;  but  to  those  who  wish  to  include  in  their  work 
pictures  of  moving  objects,  the  more  expensive  lenses  must  be 
employed,  of  which  the  Morrison  lenses  are  a  representative  type. 

With  one  or  the  other  of  the  two  lenses  named  any  work  pos- 
sible in  photography  can  be  produced. 

The  tripod  is  the  stand  on  which  the  camera  is  placed,  is  ad- 
justable, and  must  be  made  of  well-seasoned  wood;  when  not  in 
use  it  is  folded  into  compact  form,  placed  in  a  bag,  and  is  easily 
carried  in  the  hand.  One  of  the  best  forms  made  is  that  known 
as  the  Scovill  Extension  Tripod. 


This  tripod  possesses  special  advantages.     It  can   be  set    up 
ready   for  use   quicker   than   any   other,    and  with   less   trouble. 


SCOVILL  EXTENSION  TRIPOD 

When  placed  on  uneven  ground,  the  camera  it  supports  may  be 
brought  to  the  proper  level  by  simply  adjusting  the  length  of  the 
legs.  It  has  no  detachable  parts  to  be  misplaced  or  lost.  With- 
out this  tripod  valuable  time  is  often  wasted,  or  opportune 
moments  lost  in  placing  the  tripod  legs  and  changing  their  posi- 
tion to  include  just  what  is  wanted  in  a  picture,  and  to  level  the 
camera. 

Next  in  the  order  of  essentials  named  is  the  focusing  cloth  and 
the  focusing  glass. 

The  cloth  should  be  about  one  yard  square,  of  some  dark  ma- 
terial, impervious  to  light;  such  material  can  easily  be  found  in 
any  home.  Many  prefer  a  cloth  made  of  some  waterproof  ma- 
terial; this  has  the  two-fold  advantage  of  excluding  light,  and  in 
case  of  a  shower  serves  to  protect  your  camera,  etc.,  from  the  rain. 


SCOVILL  FOCUSING  GLASS. 


This  desirable  little  instrument  is  intended  to  aid  the  photog- 
rapher in  securing  a  sharply  denned  picture  on  the  ground  glass; 
to  most  people  it  is  indispensable;  the  image  on  the  glass  being 
small  and  reversed,  is  at  times  somewhat  difficult  to  determine  as 
to  exact  sharpness. 

The  dry-plate  holder  (each  holding  two  plates)  which  this  cut 
represents,  is  a  device  for  holding  the  sensitive  plate,  guarding  it 
from  light,  and  so  constructed  as  to  be  placed  upon  the  back  of 
the  camera,  in  the  place  occupied  by  the  ground  glass,  with  slides 
to  be  withdrawn  when  so  placed  that  the  image  which  was  thrown 
upon  the  ground  glass  may  then  be  thrown  upon  the  face  of  the 
plate  which  is  concealed  in  the  holder. 


The  position  of  the  face  of  the  plate  is  exactly  that  first  occu- 
pied by  the  ground  glass;  thus,  whatever  was  seen  upon  it  must 
now  be  thrown  upon  the  plate;  if  the  image  was  sharp  (a  photo- 
graphic term  for  clearly  defined)  on  the  one,  so  it  will  be  on  the 
other. 

Of  these  holders,  as  many  are  carried  into  the  field  as,  in  the 
opinion  of  the  photographer,  he  will  need  for  the  work  he  has 
before  him. 

The  articles  named  :  camera,  lens,  tripod,  cloth  for  covering 
the  head,  focusing  glass,  and  plate  holders,  comprise  all  that  is 
carried  into  the  field,  neatly  packed,  as  they  should  be,  in  proper 
cases.  This,  at  least  so  far  as  the  holders  are  concerned,  should 
never  be  neglected;  as  little  exposure  of  them  as  possible  to  light 
should  ever  be  the  watchful  rule  of  the  careful  photographer. 

The  next  lesson  will  describe  the  methods  of  using  the  articles 
named  in  this  one. 


CHAUTAUQUA  UNIVERSITY. 

LEWIS  MILLER,  PRESIDENT. 
J.  H.  VINCENT,  CHANCELLOR.  R.  S.  HOLMES,  REGISTRAR. 


TUB  Gkttp  SGlool  of 


19 

SCHOOL    HEADQUARTERS, 

4,23  Broome  Street,  ISTew  York. 


CHARLES     WAGER    BUZZ, 

Sufi,  of  Instruction,  C.  S.  of  P. 

LESSON   No.    II. 


MANAGEMENT  OF    CAMERA    AND  UENS 
IN  THE  FIEIJD. 

IN  the  previous  lesson  effort  was  made  to  fully  explain  the  ap- 
paratus named.  Attention  was  called  to  its  many  parts,  and  set- 
ting aside  the  perhaps  merited  charge  of  prolixity,  such  part  of 
each  apparatus  has  thus  far,  and  will  be,  to  the  end  of  these  les- 
sons, more  fully  explained  than  custom  would  seem  to  demand. 
We  are  writing  to  include  those  who  know  absolutely  nothing  as 
yet  of  the  matter  to  which  their  attention  is  being  called,  to  many 
students  who  are  far  away  from  any  photographer,  '.vho  have  all 
to  learn,  no  one  near  by  to  help  them  ;  to  these  detail  in  de- 
scription will  certainly  be  acceptable. 

We  now  have  the  camera  with  its  lens  in  place  in  the  center  of 
the  sliding  front  where  the  word  "  Scovill  "  appears,  the  flange  of 
which  has  been  neatly  fitted  and  firmly  fastened  with  small 
screws  ;  the  tripod,  the  focusing  cloth,  and  the  focusing  glass ; 
for  the  present  we  will  leave  the  plate-holder  behind.  Picking 
up  the  articles  named  let  us  step  out  upon  the  lawn,  taking 
position  so  that  the  sun  will  be  off  a  little  to  one  side  or  the  other, 
and  behind  us.  We  can  hardly  expect  to  secure  a  good  picture 
with  the  sun  or  strongest  light  directly  in  front  of  us,  neither  can 
we  look  for  good  effects  of  light  and  shade  (both  are  needed)  if  the 
light  be  either  immediately  over  head  or  directly  behind  us.  More, 
far  more,  depends  upon  the  proper  selection  of  the  point  of  view 
and  the  direction  of  the  light  than  many  would  suppose  ;  there  is 
a  proper  time  of  day,  a  proper  direction  from  which  the  light 
should  come  for  every  landscape  ;  a  time  when  the  shadows  will 
so  fall  as  to  give  proper  effect,  for  from  the  shadows  in  their 


relations  to  the  strong  or  high  lights,  do  we  get,  when  properly 
contrasted,  the  harmonious  whole ;  the  picture  that  always  pleases. 
Let  us  place  our  camera  here;  before  us  lies  a  view  combining 
conditions  which  will  teach  us  the  use  of  our  lens  with  its  dia- 
phragms, more  often  called  "stops."  The  first  step  to  be  taken  is 
to  choose  the  best  point  of  view.  In  choosing  this  we  are  governed 
by  the  following  considerations  :  The  sun  is  to  our  back  and  to 
the  right;  in  the  immediate  foreground  we  have  a  large  rustic  seat; 
further  along  and  to  the  left  is  a  rustic  bower  covered  with  vines ; 
in  the  middle  foreground  a  small  pool  of  water,  still  and  glassy  as 
a  mirror,  with  several  small  willows  beautifully  reflected  from 
within  it ;  further  on  to  the  left  a  magnificent  cluster  of  large 
trees;  beyond,  in  the  distance,  a  little  to  the  right,  is  a  pretty  villa 
not  so  thickly  surrounded  with  trees  as  to  obscure  its  architect- 
ural beauties  ;  in  front  of  it  a  lawn  stretching  down  to  the  little 
pool  that  is  situated,  as  stated,  in  the  middle  foreground.  The 
light  coming  from  the  direction  stated,  falls  in  such  a  way  as  to 
light  well  into  the  large  forest  trees,  casts  the  shadows  of  others 
aslant  the  lawn,  and  brings  the  projecting  angles  of  the  villa  into 
bold  relief.  This  effect  of  relief — the  bold  standing  out  from  a 
flat  surface — is  nowhere  better  seen  than  in  a  well-painted  sign: 
proper  shading  at  a  proper  angle  gives  to  the  letters  every  ap- 
pearance of  being  solid, — raised  from  the  surface. 

From  this,  it  must  be  plain  to  all  that  the  proper  relief — the 
standing  out  from  the  flat  surface — can  only  be  produced  by  pro- 
per shading,  proper  kind  of  shadows  ;  these  it  must  now  be  seen, 
cannot  be  had  to  good  effect  when  the  light,  as  before  stated,  is 
either  immediately  over  head  or  directly  in  front  or  behind. 

Having  selected  our  point  of  view,  place  the  tripod  firmly  upon 
the  ground  and  upon  it  place  the  camera,  passing  through  the 
head  of  the  tripod  the  thumb  screw  which  secures  the  camera  to- 
il, only  setting  up  the  screw  tight  enough  to  hold  the  camera  in 
place,  yet  allowing  it  to  be  turned  from  side  to  side  as  may  later 
on  be  required.  This  done,  see  that  the  camera  is  level,  look  at 
it  from  all  sides  ;  this  is  an  all  important  step,  especially  so  when 
any  architectural  object  forms  part  of  the  picture. 

The  tripod  resting  firmly,  the  camera  being  level,  next  remove 
the  cap  from  the  front  of  the  lens  and  place  the  focusing  cloth 
over  all  excepting  the  front  of  the  lens.  With  the  lens,  there  was 
sent  to  you  the  diaphragms.  Of  these  there  are  several;  they  are 
flat  thin  pieces  of  blackened  metal,  with  holes  of  various  sizes  in 
their  center  ;  they  are  also  known  as  ''  stops,"  and  are  frequently 
spoken  of  as  "  openings."  "In  focusing,  which  is  soon  to  follow, 


we  will  use  the  largest  opening  or  stop,  for  the  reason  that  the 
image  is  brighter  on  the  ground  glass,  due  to  the  letting  in  of 
more  light,  than  could  be  admitted  through  the  smaller  stops 
Having  arranged  the  stop  as  directed,  and  removed  the  cap  from 
front  of  the  lens,  next  step  to  the  rear,  raise  the  cloth  and  place 
it  over  your  head. 

What  do  you  see  ?  Nothing,  unless  you  have  used  a  camera 
before.  You  would  not  have  thought  so;  yet  there  is  quite  a  little 
knack  in  finding  the  image  on  the  ground  glass.  You  are  prob- 
ably too  near.  Raise  the  cloth  a  little  and  draw  your  head  slowly 
back,  the  image  will  soon  appear.  Now  close  the  cloth  tightly  so 
as  to  exclude  all  the  light,  moving  to  or  from  the  glass  until  you 
have  the  proper  focus  for  your  eye.  Next  loosen  the  thumb- 
screw that  holds  the  movable  part  of  the  camera,  so  that  by 
slowly  and  steadily  moving  it  to  or  from  you,  you  obtain  a  sharp 
image  on  the  glass;  this  your  focusing  glass  will  enable  you  to  do 
exactly.  In  using  it  place  it  against  the  back  side  of  the  glass  and 
your  eye  at  lens  in  the  small  end.  It  may  be  that  the  focusing 
glass  does  not  suit  your  eye  ;  it  is  adjustable  ;  the  eye-piece  can 
be  moved  in  or  out  as  may  be  needed.  Test  it,  however,  by  hold- 
ing the  ground  glass  between  your  eye  and  the  light,  the  ground 
side  from  you,  and  move  the  eye-piece  until  the  glass  on  ground 
side  looks  rough  and  distinct,  as  it  will  do  under  such  conditions. 
In  the  landscape  before  us  so  move  your  camera  by  turning  to 
right  or  left  on  the  tripod  as  to  bring  the  rustic  seat  into  or  near 
the  upper  right  hand  corner  of  the  glass  and  the  villa  nearly  to 
the  lower  left  hand  corner,  as  you  see  the  inverted  image  before 
you.  This  upside  down  condition  of  things  will  confuse  you  at 
first,  and  so  will  the  placing  on  the  right  of  objects  which  are  on 
the  left,  and  those  of  the  left  on  the  right.  However,  you  will 
soon  become  accustomed  to  this  new  order  of  things.  In  examin- 
ing the  image  you  may  find  that  the  villa  is  not  all  upon  the  plate. 
To  bring  it  on,  raise  the  sliding  front  until  it  is  all  upon  the  plate, 
and  a  fair  piece  of  sky  as  well.  If  in  doing  this  you  have  not  lost 
your  rustic  seat  in  foreground,  all  is  right.  If  you  have,  then  you 
are  too  near  your  objects  ;  move  back,  taking  up  a  position  that 
will  give  you  on  the  ground  glass  all  the  objects  you  wish  to  have 
upon  the  sensitive  plate.  Your  sliding  front,  as  is  now  seen,  will 
bring  in  more  foreground  by  lowering,  more  sky  by  raising.  Be 
sure  to  fasten  tightly  when  proper  position  for  it  has  been  found; 
and  fasten  also  the  camera  to  the  tripod  by  setting  up  the  screw 
beneath.  Nothing  has  been  said  as  to  letting  down  and  making 
fact  the  folding  bed.  This,  it  is  assumed,  has  been  done. 


In  this  picture  you  will  not  find  any  use  for  the  swing-back  ; 
indeed,  it  is  not  often  required  for  field  work;  then  only  as  a  rule 
when  you  are  so  placed  as  to  have  an  object  immediately  in  the 
foreground  ;  so  near  that  you  are  unable  to  obtain  sharpness.  In 
this  case,  set  back  the  top  which  lengthens  the  foreground  focus, 
so  that  the  whole  may  be  equalized. 

When  not  in  use,  be  careful  to  have  it  firmly  fixed  at  right 
angles  to  the  bed  or  platform. 

Now  to  focus  the  image  which  has  been  arranged  upon  the 
glass.  Choose  some  object  in  the  middle  foreground,  the  bark  of 
a  tree,  a  cluster  of  rocks  that  are  moss-covered,  any  object,  in 
short,  on  which,  by  aid  of  your  glass,  you  can  sharp!/  focus. 
This  done,  examine  the  rustic  seat  in  near  foreground,  and  the 
villa  in  right  distance ;  both  are  beyond  doubt  lacking  in 
sharpness;  now  is  the  time  to  see  what  the  stops  will  do.  See 
if  by  using  the  next  smallest  if  sharpness  is  had;  if  not,  the  next, 
until  all  parts  of  the  image  are  sharp;  this,  within  fairly  reason- 
able bounds,  providing  the  lens  is  suited  to  the  size  of  plate  in 
use,  can  be  had;  but,  as  you  have  seen,  at  a  great  sacrifice  of 
light;  this,  however,  we  cannot  avoid.  In  using  the  stops  or  dia- 
phragms, always  use  the  one  with  the  largest  opening  that  will  give 
you  the  desired  definition  or  sharpness;  this  for  two  reasons;  you 
get  more  light  on  the  plate,  thus  making  your  picture  in  a  shorter 
time,  and  you  get  a  more  crisp,  brilliant,  and  pleasing  result. 
Before  the  camera  has  been  long  in  use,  the  careful  student  will 
find  that  the  nearer  an  object  is,  the  further  apart  will  be  his  lens 
and  his  ground  glass  when  he  makes  sharp  the  image;  the  closer 
together  when  the  object  is  at  a  greater  distance. 

He  will  also  have  observed  that  when  the  focus  has  been  found 
for  an  object  75  to  100  feet  away,  and  the  proper  stop  has  been 
used,  that  all  beyond  the  distance  named  is  equally  sharp. 
Knowing  this,  a  mark  on  the  folding  bed  is  made,  and  all  pictures 
within  the  distances  named,  are  made  without  using  the  ground 
glass;  the  camera  is  placed  at  the  marked  spot,  and  the  photog- 
rapher goes  ahead  with  certainty  of  success. 

Were  it  not  so,  the  beautiful  pictures  of  moving  objects  could 
not  be  made  ;  to  locate  them  on  plate  a  little  instrument  is  placed 
upon  the  camera,  termed  a  finder.  Of  this,  and  its  uses,  more 
will  be  said  when  the  methods  of  making  instantaneous  pictures 
are  described. 

The  student  is  urged  to  work  steadily  with  his  camera,  master 
the  sliding  front  and  other  parts  ;  before  long  he  can  try  a  sensi- 
tive plate. 


CHAUTAUQUA    UNIVERSITY. 

LEWIS  MILLER,  PRESIDENT. 
J.  H.  VINCENT,  CHANCELLOR.  R.  S.  HOLMES,  REGISTRAR. 


Tie  Glautaup  Seoul  of 


9 

SCHOOL    HEADQUARTERS, 
23  Broorne  Street,  New  York. 


CHARLES     WAGES    HIFLL, 

Supt.  of  Instruction,  C.  S.  of  P. 


LESSON    IV. 

TUB     SENSITIVE    PI^ATB:     HOW    IT    IS 
P ACKBD  ;  HOW  TO  PLACB  IN  1 1 OLIJKR. 

OF  plates  many  manufacturers  make  several  brands.  Some  are 
intended  for  instantaneous  work,  others  for  landscape,  or  subjects 
of  still  life,  and  plates  for  transparencies,  such  as  may  be  hung  in 
the  window,  made  into  lamp  shades,  or  for  use  in  the  lantern;  all 
are  packed  in  the  same  way. 

All  that  I  have  ever  seen  are  put  up  in  paper  boxes  containing 
one  dozen,  in  the  following  manner:  On  the  bottom  of  the  box  a 
plate  is  laid  face  up — that  is,  the  side  on  which  the  sensitive  pre- 
paration is  placed;  on  this  either  a  thin  piece  of  paper  is  laid,  or 
some  other  method  is  used  to  keep  this  surface  from  coming  in 
contact  with  the  one  next  above  it,  which  is  placed  face  down. 
The  third  plate  is  placed  back  to  back  to  the  second  plate,  and 
so  on  face  to  face,  or  back  to  back,  to  the  top  plate,  which  is 
back  up. 

Before  opening  the  box  containing  the  plates  provide  yourself 
with  a  broad,  flat,  long-haired  and  very  soft  brush  of  camel  or 
sable  hair  at  least  two  inches  wide;  light  your  ruby  lantern,  lay 
the  brush  on  a  clean  piece  of  paper  at  your  side,  and  all  is  ready 
for  opening  the  box  containing  the  sensitive  plates.  It  is  to  be 
assumed  that  in  an  outer  room  you  have  opened  and  thoroughly 
dusted  and  cleaned  the  plate-holders  or  shields,  as  they  are  as 
often  called.  This  should  be  done  quite  often;  if  not,  you  will 
probably  find  on  your  negatives  transparent  spots,  the  result  of 
small  specks  of  dust  from  dirty  holders. 

If  you  use  the  kind  of  holder  referred  to  in  cut  in  Lesson  I, 
you  will  notice  a  slide  at  the  left;  this  acts  as  a  partition  between 


the  two  plates;  on  either  side  is  a  flat  spring  of  sheet  brass, 
which  presses  against  the  back  of  each  plate,  holding  it  firmly 
in  position.  When  this  partition  or  slide  is  in  place,  it  is  held 
there  by  a  catch  on  the  edge  of  the  holder.  The  slide  on  the 
right  is  the  one  which  is  drawn  out  when  holder  is  placed  on  the 
camera,  and  when  all  is  ready  to  make  the  exposure;  of  these 
there  are  two — one  in  front  of  each  plate;  the  other  in  the  cut  is 
seen  as  closed. 

Before  we  close  the  door  of  your  dark  room  let  us  loosen  the 
catch  on  the  slide  between  the  two  plates,  and  pull  each  one  in 
each  holder  out  a  short  distance  and  place  them  on  the  shelf  in 
order  at  our  left,  closing  tightly  the  slides  that  are  in  front  of  the 
plates.  This  done,  we  close  the  door  and  fasten  it  on  the  inside 
to  keep  out  any  curious  friend  who  on  entering  would  bring  in  a 
very  bad  friend — light.  This  precaution  taken,  we  sit  down  com- 
fortably in  our  chair  facing  the  broad  shelf,  having  on  one  side 
the  empty  plate-holders,  on  the  other  the  brush,  and  in  front  the 
box  of  sensitive  plates;  these  to  begin  with  shall  be  Carbutt's  B 
or  landscape  plates. 

Take  the  box,  open  it  with  care,  removing  lid  and  turning  back 
to  each  side  the  paper  that  covers  the  plates;  then  by  the  edge 
gently  raise  the  top  plate,  which  we  find  back  up.  This  can  easily 
be  determined,  if  in  doubt,  by  holding  it  at  an  angle  towards  the 
ruby  light,  the  back  showing  a  bright  reflection,  the  face  a  very  dull 
one.  Take  the  plate  by  one  corner  in  the  left  hand,  being  careful 
not  to  touch  its  face  except  just  at  the  corner,  and  pass  the  broad 
soft  brush  gently  over  the  sensitive  surface  to  remove  any  parti- 
cles of  dust  that  in  the  shaking  it  has  had  in  the  box  may  have 
lodged  on  it.  This  done,  lay  down  the  brush,  take  plate  in  the 
right  hand,  and  having  withdrawn  the  partition  slide  from  the 
plate-holder,  put  the  p  ate  just  dusted  carefully  into  one  side  of 
it,  having  face  to  the  outside;  dust  another  plate  and  put  it  into 
holder,  face  out,  as  before,  thus  bringing  the  backs  together;  then 
slip  in  the  partition  slide  between  the  two  plates  and  fasten  it; 
be  sure  that  the  other  slides  are  also  closed,  and  holder  No.  1 
with  two  plates  is  ready  for  use. 

Be  careful  in  sliding  in  the  plates  that  you  do  not  bring  the 
face  in  contact  with  the  holder,  otherwise  they  may  be  scratched; 
the  same  care  must  be  used  in  taking  them  out.  If  any  plates 
are  left  in  box,  mark  the  number  in  it,  the  kind  of  plate,  secure 
it  by  a  string  and  put  away  in  the  darkest  corner  of  your  dark 
room. 

This  work  may  appear  to  be  most  simple,  and  so  it  is;   all  things 


appear  simple  to  those  who  know  how  to  do  them  and  are  in  con- 
stant practice,  but  to  the  beginner  the  most  simple  seems  difficult 
until  mastered.  It  will  be  awkward  work  to  you  the  first  time; 
you  will  not  ba  able  to  work  with  ease  in  almost  total  darkness; 
you  will  probably  drop  a  plate  or  two  on  the  floor;  some  of  them 
will  be  put  into  the  holder  wrong  side  about,  or  scratched  putting 
them  in,  and  without  doubt  you  will  cut  your  fingers  with  the 
edges  of  the  glass.  None  of  these  blunders  will  be  made  oftener 
than  is  necessary  to  teach  you  not  to  do  it  again. 

There  is  considerable  knack  in  handling  a  plate  so  that  its  sur- 
face shall  not  be  injured  or  your  fingers  cut;  to  save  the  latter,  be 
careful  not  to  draw  the  fingers  along  the  edges;  if  you  do,  it  will 
probably  spoil  the  plate  and  hurt  the  fingers 


CHAUTAUQUA  UNIVERSITY. 

LEWIS  MILLER,  PRESIDENT. 
J.  H.  VINCENT,  CHANCELLOR.  R.  S.  HOLMES,  REGISTRAR. 


THE 


[Jfjauisaiiqiia  $cjjool  of  photograph}, 

SCHOOL    HEADQUARTERS, 

423  BROOME  STREET,  NEW  YORK. 


CHARLES     WAGER     HULL, 
Supt.  of  Instruction,  C.  S,  of  P. 


LESSON   V. 

EXPOSURE    OF    PIRATE. 

No  FIXED  rule  can  be  given  for  this  part  of  the  photographic 
operation.  No  end  of  conditions  serve  to  change  the  time  required 
in  a  day's  work  out  of  doors  ;  in-doors  it  is  much  more  simple, 
shortening  the  time  as  we  approach  midday  and  lengthening  as 
we  pass  into  the  later  hours  of  the  afternoon. 

From  eleven  to  two  o'clock  is  about  the  time  when  exposure 
would  be  shortest,  an  hour  or  two  before  sunset  the  slowest,  for 
then  we  often  have  in  the  summer  months  a  peculiar  red  or  yel- 
lowish light  which  renders  photographing  almost  impossible. 

The  later  spring  and  early  summer  months  as  a  rule  give  our 
quickest  lights  ;  the  fall  months,  though  the  day  may  be  clear  to 
the  eye,  are  often  hazy  and  yellowish  in  their  color  of  light. 
Longer  exposure  will  sometimes  give  us  all  we  desire,  always  pro- 
viding there  is  no  haze.  This  no  amount  of  time  will  ever  offset. 

When  a  haze  or  fog  obscures  to  the  eye  the  distance,  do  not 
make  any  attempt  to  work  on  distant  subjects.  It  may  be  that 
subjects  very  near  can  be  made,  there  being  less  haze  or  fog  to 
look  through.  This,  however,  depends  altogether  on  its  density. 

Under-exposure  and  over-exposure  outside  of  certain  com- 
paratively narrow  limits,  is  in  a  general  sense  fatal  to  good  work  ; 
yet  there  is  what  photographers  call  latitude  of  exposure,  which, 
be  it  more  or  less  than  just  right,  is  not  of  necessity  fatal  to  good 
work. 

For  instance,  if  four  seconds  should  be  exactly  the  right  time 
of  exposure  to  give  on  a  certain  subject,  and  either  two  or  six 
seconds  should  have  been  given,  the  negative  in  the  hands  of  a 
skilled  photographer  would  not  be  lost  ;  it  would  be  noticed  in 

3 


the  operation  of  development,  and,  as  will  be  later  shown,  the 
method  of  treatment  would  be  so  changed  as  to  produce  a  good 
negative.  The  main  trouble  in  over-exposed  and  under-exposed 
plates  lies  in  the  fact  that  we  do  not  discover  the  error  made 
soon  enough  to  apply  the  remedy.  Of  this  more  will  be  written 
when  the  lesson  on  development  is  in  hand. 

On  one  occasion,  to  test  this  question  of  latitude  of  exposure, 
the  writer  went  so  far,  when  making  a  group  of  sixteen  people  in 
a  well-shaded  grove  away  from  all  direct  sunlight,  as  to  give  an 
exposure  of  two,  four,  six,  eight,  ten  and  twelve  seconds.  My 
judgment  before  making  the  exposure  was  that  six  seconds  would 
be  about  the  right  time.  What  was  the  result  ?  Every  plate  was 
good,  alone  excepting  the  one  exposed  two  seconds.  This  was 
certainly  great  latitude,  and  would  to  the  uninitiated  seem  to 
prove  that  the  art  of  exposing  was  no  great  art  after  all.  Such 
is  far  from  being  the  fact. 

In  this  case  I  had  the  advantage,  for  I  was  sure  that  I  had 
both  under  and  over-exposed.  Knowing  this,  I  first  developed 
the  one  which  I  thought  to  be  right  in  time,  and  finding  by  using 
the  normal  developer  that  it  was  so,  I  had  only  to  make  changes 
hereafter  to  be  described  to  meet  the  conditions  of  those  which 
had  had  the  extremes.  The  one  made  in  two  seconds  was  defi- 
cient in  proper  detail  ;  the  ten  and  twelve  were  good,  but  not  as 
brilliant  as  the  other  three.  From  this  it  will  be  seen  that  if, 
after  having  been  out  for  a  day's  work,  you  should  find  that  for 
any  reason  you  had  erred  on  one  or  other  side  in  the  exposure,  if 
not  too  great,  you  can,  knowing  the  error,  do  much  to  make 
good  the  blunder. 

When  the  exposure  has  been  100  much  one  way  or  the  other, 
no  amount  of  coaxing  or  fussing  will  give  a  satisfactory  result. 

When  in  doubt  give  the  doubt  to  the  side  of  over-exposure. 
Time  enough  must  always  be  given  to  impress  the  image  on  the 
plate  ;  you  can  restrain  an  over-exposure,  but  no  amount  of  coax- 
ing will  ever  bring  out  in  the  negative  that  which  has  not  been 
put  there  by  your  lens.  You  might  as  well  give  it  up  first  as  last. 

Photography  will  do  a  great  deal  now-a-days,  but  it  will  not 
make  an  instantaneous  picture  of  a  yellow  horse  against  a  green 
background  ;  it  might  do  something  for  you  if  the  horse  was 
white.  This  brings  up  another  phase  of  the  subject,  which  at 
first,  unless  you  stop  to  think,  will  give  you  trouble.  The  photo- 
graphic character  of  subjects  vary  as  much  as  do  the  subject. 

A  view  of  a  house  that  is  painted  white  will  require  less  time 
for  exposure  than  one  that  is  painted  with  the  reds,  browns  and 

4 


yellows  so  common  of  late.  Spring  foliage  will  require  less  time 
than  summer  foliage  that  has  faded  somewhat,  while  the 
glorious  tints  of  the  fall  are  practically,  if  not  wholly,  beyond 
our  art.  People  with  sallow  complexions  and  dark  dresses  will 
require  more  time  than  the  child  or  young  person  whose  com- 
plexion is  clear  and  bright,  and  clothing  light  in  color. 

Dark  eyes,  as  a  rule,  photograph  well ;  light  blue  eyes  do  not. 
An  ordinary  open  view  with  a  Waterbury  lens  and  medium  stop 
will  probably  require,  on  a  good  clear  day,  about  two  to  three 
seconds'  exposure;  with  a  Morrison  wide  angle,  half  that  time.  If 
the  view  to  be  made  is  through  a  well-wooded  lane  or  roadway, 
or  of  a  house  well  hidden  in  trees,  the  time  will  go  to  ten  or 
twelve  seconds  ;  if  of  a  dull  lighted  interior  it  may  take  hours. 
From  what  I  have  written  it  may  be  that  my  reader  is  fearful  he 
will  never  know  how  mudh  time  to  give.  Do  not  despair,  you  will 
learn  more  easily  than  you  imagine.  I  have  a  certain  rule  as  to 
the  time  required  for  any  given  subject,  the  rule  which  1  fancy 
must  be  the  rule  of  all  out-door  workers  ;  it  is  this  :  The  point  of 
view  having  been  selected,  the  camera  in  position,  everything 
ready  for  the  exposure,  I  stop  a  moment,  look  carefully  over  the 
view,  call  to  mind  a  certain  view  which  in  character  of  subject 
and  conditions  of  light  is  similar  to  the  one  before  me,  and  to 
which  the  right  time  had  been  given,  judge  this  one  by  that,  and 
expose  accordingly  ;  give  it  the  same  or  more  or  less  as  in  my 
judgment  it  may  seem  to  demand.  In  my  memory  there  is  stored 
away  for  such  use  a  few  of  such  instances,  which  I  may  be  allowed 
to  term  samples;  one  or  other  of  them  is  quite  certain  to  meet  the 
present  want ;  by  it,  as  stated,  I  measure  this.  Of  such  there  would 
not  be  many :  a  broad  open  view  with  distance,  a  view  through  a 
road  well  shaded  by  trees  on  either  side,  a  view  in  woods  with 
heavy  foliage,  a  view  through  a  grove  with  medium  distance  and 
rocky  foreground  ;  such  and  others  that  I  do  not  need  to  name, 
Each  have  to  me  a  certain  photographic  value  ;  each  I  know  well 
as  to  time  given.  I  choose  my  sample,  as  I've  termed  it,  and  use 
my  judgment.  To  one  who  has  no  standard  in  his  mind  this  may 
appear  difficult  to  understand  ;  later  on,  when  you  have  made  a 
few  good  negatives,  you  will  have  them  impressed  on  your  memory 
and  can  then  choose  your  own  samples.  There  seems  to  be  a 
sort  of  intuition  about  this  matter  of  exposure  that  makes  the 
subject  hard  to  explain,  for  even  after  you  have  taken  the  cap 
from  the  lens,  your  mind  made  up  as  to  the  time,  the  chances  are 
more  than  even  that  you  will  change  it  to  longer  or  to  shorter  ex- 


posure,  which  nine  times  out  of  ten  will  be  the  right  thing  to  do. 
This,  of  course,  is  after  experience  has  been  had. 

An  authority  in  photography  said  many  years  ago:  "  In  the 
whole  range  of  photographic  manipulations,  the  sum  of  which  goes 
to  make  up  the  perfect  picture,  there  is  not  one  of  more  importance 
than  the  correct  time  of  exposure  in  the  camera."  This  is  true 
to-day. 

In  generalities  I  think  enough  has  been  written,  let  us  now  take 
our  camera  and  plates  and  have  "  a  shot,"  as  we  call  it ;  in  other 
words,  let  us  make  our  first  exposure.  See  that  the  camera  and 
lens  are  clean  and  free  from  dust ;  see  that  the  holders  are  tightly 
closed  before  leaving  the  dark-room  ;  see  that  they  are  in  a  good 
box  to  shield  them  from  light,  not  forgetting  that,  although  light 
we  must  have,  we  only  want  that  which  passes  through  our  lens  ; 
it  is  our  friend,  yet  by  carelessness  it  will"  prove  our  worst  enemy. 

The  plate  holders  must  always  be  well  cared  for,  never  laid 
about  upon  the  grass  in  the  sun,  keep  all  in  box  but  the  one  in 
use.  Let  us  put  up  the  camera  here  ;  a  good  foreground,  mode- 
rate distance,  bright  foliage.  Set  tripod  firmly,  focus  with  a  large 
stop  in  lens  on  an  object,  say  a  hundred  or  so  feet  away,  adjust 
the  sliding  front,  and  so  turn  the  camera  to  one  or  other  side 
until  you  have  upon  the  ground  glass  the  subject  you  wish.  Keep 
camera  level,  changing  the  stop  to  the  size  that  will  make  fore- 
ground and  distance  both  clear  and  distinct  upon  the  glass;  if 
immediate  foreground  is  not  as  sharp  as  it  should  be,  draw  back 
the  swing  back  at  top  until  it  is;  screw  up  tightly  all  the  set 
screws,  and  cap  the  lens. 

After  these  things  have  been  done  remove  the  ground  glass,  take 
plate  holder  from  box,  throw  your  focusing  cloth  over  it,  close 
box,  and  put  holder  in  place  of  the  ground  glass;  draw  the  slide 
with  a  steady  motion  until  nearly  out,  then  with  a  quick  motion 
entirely  out,  keeping  cloth  over  it  the  whole  time,  and  letting  it 
remain  over  holder  until  returned  to  box.  You  are  now  ready  to 
expose;  study  object,  settle  in  your  mind  the  time  you  should 
give — let  us  say  it  is  four  seconds  on  a  Keystone  B  plate — uncap, 
give  the  time  and  re-cap.  In  taking  off  and  putting  on  cap  do  it 
quickly  and  be  careful  not  to  jar  or  shake  camera,  particularly 
when  you  uncap;  if  you  do  you  may  cause  vibration,  thus  render- 
ing the  picture  indistinct. 

The  lens  being  capped,  raise  the  corner  of  the  focusing  cloth 
that  covers  the  holder,  and  return  the  slide  you  had  removed;  do 
this  by  a  steady,  quick  motion,  shielding  it  with  the  cloth  and 
putting  in  the  slide  squarely,  not  one  corner  first,  for  inside  there 

6 


is  a  spring  to  cut  off  the  light  when  slide  is  withdrawn;  examine 
it  when  empty  and  you  will  see  why  it  must  go  in  square.  Be  par- 
ticular about  this. 

Having  now  made  one  exposure,  which  we  will  assume  to  be 
exactly  right,  let  us  make  two  more,  which  we  will  find,  later  on, 
are  wrong;  one  say  for  two  seconds  or  a  little  less,  and  one  for  six 
or  seven  seconds,  giving  us  for  a  future  lesson  one  that  is  right,  one 
that  is  under-exposed  and  one  that  is  over-exposed;  their  action 
under  the  developer  in  the  next  lesson  will  give  us  the  proof. 

Later  it  will  be  seen  that  the  plate  to  which  was  given  four 
seconds  proves  to  be  just  right — a  good,  clean,  clear,  sharp  nega- 
tive of  fine  intensity,  all  that  we  want.  You  now  have  a  sample, 
as  I  have  termed  it,  or  standard  for  that  character  or  class  of 
views;  for  such,  in  future,  you  now  have  something  to  measure 
another  exposure  of  similar  subject  by;  if  of  little  thicker  foliage 
or  foreground,  or  little  less  brilliant  light,  then  in  your  judgment 
a  little  more  time;  if  the  reverse,  then  a  little  less  time. 


CHAUTAUQUA  UNIVERSITY. 

LEWIS  MILLER,  PRESIDENT. 
J.  H.  VINCENT,  CHANCELLOR.  R.  S.  HOLMES,  REGISTRAR. 


THE 


frjautauqua  $cljool  of 


SCHOOL    HEADQUARTERS, 

423  Broome  Street,  New  York. 

CHARLES     WAGER     HULL, 
Supt.  of  Instruction,  C.  S.  of  P. 


LESSON  VI. 

DEVELOPMENT. 

DEVELOPMENT  is  that  part  of  the  photographic  art  which  brings 
to  sight  the  latent  or  hidden  image  on  the  sensitive  plate  after  it 
has  been  exposed  in  the  camera ;  it  is  a  delicate  operation,  re- 
quires close  attention,  good  eyesight  and  judgment,  oftentimes 
patience  ;  always  care  and  cleanliness.  It  can  only  be  carried 
forward  when  all  but  the  ruby  light  has  been  excluded ;  if  suc- 
cessful in  it,  we  have  our  greatest  photographic  joy  ;  if  not,  our 
greatest  disappointment ;  for  if  a  success,  we  have  the  negative 
from  which,  with  care  in  its  handling,  hundreds  of  charming 
prints  may  be  made.  Before  proceeding  to  develop  the  plates 
exposed  in  the  last  lesson,  let  us  put  our  house  in  order,  make  the 
developer,  etc.,  so  that,  when  we  close  the  door  of  the^dark  room, 
everything  will  be  at  hand  and  just  where  it  should  be.  A  good 
motto  for  the  dark  room  would  be  the  good  old  one  of  "  A  place 
for  everything,  and  everything  in  its  place,"  not  only  for  the 
reason  that  it  is  always  well  to  have  it  so,  but  in  the  darkness -of 
the  dark  room  it  must  be  so,  otherwise  we  will  not  be  able  to  work. 
So  dim  is  the  light,  excepting  only  just  before  us,  that  if  any- 
thing be  wanted,  we  must  know  just  where  to  put  a  hand  to 
find  it. 

At  all  times,  before  commencing,  wash  thoroughly  each  article 
that  is  to  be  used  ;  cleanliness  in  photography  is  but  the  synonym 
for  success.  The  developer  which  we  shall  first  use  will  be  made 
on  Carbutt's  formula  ;  it  differs  but  little  from  many  others,  is 
simple,  and  works  satisfactorily.  Just  here  let  me  impress  one 
thing  upon  the  student.  During  these  lessons,  use  this  developer 
only  ;  under  no  circumstances  try  any  other  ;  good,  most  excel- 
lent work  can  be  made  with  it.  Leave  experiments  for  the  future, 


follow  instructions  closely  ;  if  you  do  not,  confusion  and  failure 
will  result.  Do  not  think  that  I  would  have  you  believe  that  this 
is  the  only  good  developer ;  there  are,  doubtless,  many  as  good,  it 
may  be  many  better.  I  only  wish  you  to  have  one  set  of  formulas 
on  hand  while  learning,  afterward  you  are  welcome  to  the  per- 
plexity that  will  come  of  the  thousands  which  you  will  read  of 
and  hear  of.  As  a  rule,  almost  without  an  exception,  beginner 
make  very  poor  work.  There  is  no  reason  why  they  should  make 
good  work.  They  blame  their  formulas  instead  of  their  own  want 
of  knowledge  and  practice  ;  somebody  says  use  so-and-so,  an- 
other something  else  ;  the  work  does  not  improve,  discourage- 
ment follows,  sometimes  the  charming  art  is  given  up  in  despair. 
Stick  to  the  simple  rules  here  given,  and  you  are  sure  to  make 
good  work. 

Now  for  the  chemicals  needed  to  compound  the  developer  : 

Sulphite  of  soda,  crystals 1  pound. 

Carbonate  of  potash,  granulated 1       " 

Carbonate  of  soda,  granulated 1 

Pyrogallic  acid 4  ounces. 

Sulphuric  acid 1  ounce. 

Bromide  of  potash 1 

This  quantity  of  chemicals  will  give  you  enough  developer  for 
nearly  three  hundred  plates  of  6^  by  8£  size,  and  will,  if  used 
with  care  and  bought  of  a  conscientious  dealer  in  photographic 
chemicals,  not  cost  you  much  over  one  cent  for  each  plate,  refer- 
ence being  had  to  proportions  given  below,  and  used  on  plates  to 
which  proper  exposure  has  been  given. 

To  compound  the  developer  for  use,  proceed  as  follows  :  Pro- 
cure two  twelve-ounce  bottles  of  clear  white  glass,  for  reason 
that  you  can  always  see  if  they  are  clean,  with  well-fitting  corks  ; 
mark  one  No.  1,  pyro,  the  other  No.  2,  potash.  This  done,  take 
th,e  eight-ounce  graduate,  put  into  it  five  ounces  of  good  soft 
spring  water,  or  better  still  if  in  doubt  as  to  the  quality  of  the 
water,  water  from  melted  ice.  Weigh  and  add  two  ounces  of  sul- 
phite of  soda  crystals,  stir  with  a  glass  rod  or  stick  until  dis- 
solved, then  add  slowly  half  a  dram,  fluid  measure,  of  sulphuric 
acid  ;  to  this  add  240  grains  of  pyrogallic  acid  :  when  dissolved 
fill  up  to  eight  ounces  with  water. 

Next  take  the  bottle  which  has  been  marked  No.  1,  pyro,  place 
in  it  the  funnel,  into  the  neck  of  which  you  have  first  placed  a  lit- 
tle wad  of  clean  wet  cotton  ;  pour  the  solution  into  funnel,  having 
cotton  loose  enough  to  allow  it  to  trickle  slowly  into  bottle. 
This  solution  is  good  for  use  so  long  as  it  is  clear.  When  it  be- 
comes opaque  or  muddy  looking  it  must  be  rejected. 


Next  make  up  solution  for  the  bottle  marked  No.  2,  alkali,  by 
dissolving  one  ounce  each  of  potash  and  soda  in  five  ounces 
of  water  ;  then  add  water  to  make  eight  ounces  ;  filter  in  same 
way,  being  sure  that  filter  has  been  thoroughly  washed.  In  hot 
weather,  when  chemicals  work  more  rapidly  than  in  winter,  it  is 
well  to  add  to  No.  1,  pyro,  about  fifteen  grains  of  bromide  of 
potash.  The  contents  now  in  the  two  bottles  form  what  is  known 
as  stock  solution,  and  for  the  process  of  developing  are  used  as 
follows  : 

Water  (as  above) 4  fluid  ounces. 

No.  1,  pyro 2     "     drams. 

No.  2,  alkali 2     " 

Of  this,  in  the  proportions  given,  as  much  may  be  mixed  as  at 
one  sitting  is  likely  to  be  needed. 

The  developer  being  ready,  wash  the  pan  or  tray  in  which  it  is 
to  be  used  (which  should  be  of  size  known  as  7  by  9  inches), 
and  place  over  large  pan  described  in  a  previous  lesson,  in  front 
of  the  lighted  ruby  lantern.  Place  the  holders  containing  the 
exposed  plates,  and  the  developer  in  handy  position  within  reach, 
close  and  fasten  dark  room  door,  and  take  your  seat  facing  lan- 
tern and  tray,  in  which  plate  is  to  be  developed. 

All  being  ready,  remove  the  slide  which  divides  the  plates  in 
holder,  and  let  the  plate  to  which  four  seconds'  exposure  was 
given,  slide  out  slowly  face  up  to  prevent  scratching  the  film  on 
face  of  plate,  close  holder  and  lay  the  plate  in  the  tray  face  up 
(the  dull  looking  side),  then  with  a  sweeping  motion  from  one 
sideto  the  other,  throw  the  developer  over  it  ;  do  not  pour  upon 
one  spot,  but  gently  sweep  or  dash  it  over  the  whole  face. 

This  done,  move  the  tray  from  side  to  side,  being  careful  to 
have  the  solution  wash  over  all  parts  of  the  plate  and  keep  gently 
in  motion.  Should  an  air  bubble  appear  on  any  part  of  plate, 
gently  touch  with  the  finger  and  break  it,  otherwise  you  will  have 
a  spot  on  which  the  developer  not  acting  is  after  the  process  of 
fixing  transparent.  In  a  few  moments  a  shadowy  or  darkening 
appearance  on  part  of  the  plate  will  be  noticed  gradually  grow- 
ing in  distinctness  ;  this  will  be  the  high  lights,  the  sky,  or  ob- 
jects of  a  light  color  on  which  the  strongest  light  has  fallen,  fol- 
lowed by  an  indistinct  outline,  as  it  lies  in  the  tray,  of  the  view  or 
picture  thrown  upon  the  plate  by  the  lens.  In  a  moment  or  two 
it  will  slightly  fade  from  view,  become  less  distinct ;  then  with  the 
thimble  on  your  forefinger  slip  the  point  of  the  little  spear  on 
thimble  under  plate  and  raise  it  from  the  tray  ;  hold  it  up  to  the 


light  and  examine  as  to  its  intensity  and  the  detail  of  foliage,  and 
see  if  the  objects  which  were  in  shadow  have  all  appeared. 

If  not  quite  intense  enough,  in  other  words,  so  opaque  in  the 
sky  as  to  shut  out  all  light  as  viewed  by  the  ruby  light  ;  if  the 
details  in  the  shadows  have  not  appeared,  the  bark  on  the  trees 
be  not  distinct,  replace  it  in  the  solution  and  continue  the  opera- 
tion until  these  conditions  are  had.  When  had,  wash  it  with  a 
gentle  stream  of  water  from  the  upper  pail,  and  it  is  ready  to 
place  in  the  alum  solution.  This  we  will  not  do  in  this  lesson, 
but  will  stop  with  the  development,  assuming  that  it  can  be  done, 
that  the  lessons  may  be  more  easily  divided  into  the  different 
processes. 

Next,  let  us  take  the  plate  to  which  we  gave  two  seconds  or  a 
little  less,  treat  this  in  exactly  the  same  way,  and  we  will  find 
that  it  "  comes  up,"  as  photographers  say,  very,  very  slowly. 
We  wait  patiently,  but  the  details  do  not  appear  in  the  shadows, 
the  high  lights  become  very  opaque  and  intense  ;  there  is  much 
more  of  the  plate  on  which  nothing  appears  than  there  was  in  the 
other  ;  vre  continue  twice  as  long  in  our  efforts  to  "get  something 
out ;"  it  does  not  come  ;  we  give  it  up  and  wash  as  we  did  the 
other. 

Lastly,  we  take  the  other  and  last  plate,  to  which  we  gave  an 
exposure  of  seven  or  eight  seconds  ;  treat  this  as  the  others  ; 
almost  instantly  we  notice  the  action  of  the  developer  ;  it  works 
rapidly  ;  the  whole  view  seems  to  flash  up  at  once,  detail  in  shad- 
ows, everything  "  comes  up"  in  a  jiffy  ;  it  appears  to  finish  at 
once  ;  we  take  it  from  the  tray,  and  to  stop  further  action  of  de- 
veloper wash  it.  Here  we  will  let  them  rest  for  future  treatment, 
although  the  operation  is  in  practice  a  continuous  one.  For  each 
plate  a  fresh  solution  must  be  used  ;  this  I  advise,  though  some 
use  it  for  two  or  more  plates  ;  at  all  events  do  not  do  so  during 
these  lessons. 

Between  each  plate  wash  the  tray  by  playing  the  little  hose  into 
it  to  remove  any  of  the  old  solution  that  has  become  a  dark  red- 
dish color. 

The  amount  of  solution  named  above  is  really  more  than  you 
require  ;  when  skilled,  you  can  work  well  with  about  three  ounces 
in  a  tray  of  size  given  ;  while  a  little  awkward,  the  quantity  named 
will  be  safer.  In  a  general  way  I  have  aimed  to  describe  the  ac- 
tion of  a  plate  under  three  conditions  of  exposure — proper  time, 
too  little,  and  too  much.  If  in  developing  a  plate  that  has  had 
the  right  exposure  given  it,  you  should  stop  short  in  the  develop- 
ment, you  will  find  the  details  in  the  poorly  lighted  parts  of  the 


plate  are  wanting,  and  the  intensity  of  the  high  lights  and  sky  not 
dense  enough  to  cut  off  the  light  when  you  come  to  print  it  on 
paper.  This  intensity  should  be  such  as  to  give,  when  the  print 
is  made,  just  a  faint  tinge  to  the  paper,  not  so  dense  as  to  stop 
all  light  and  leave  the  paper  a  pure  white,  nor  lacking  in  inten- 
sity to  such  a  degree  as  to  allow  the  passage  of  too  much  light  as 
to  make  a  dark,  dull,  heavy  sort  of  sky.  If  we  push  the  develop- 
ment in  the  under-exposed  plate  in  our  efforts  to  get  out  the 
details,  we  will  have  the  sky  very  dense,  and,  lacking  the  details, 
we  have,  when  finished,  a  large  portion  of  the  plate  that  is  little 
more  than  clear  glass,  giving  us  a  negative  of  severe  contrasts, 
and  worthless,  yielding  a  print  with  an  absolutely  white  sky  and 
heavy  dark  shadows. 

The  over-exposed  plate  will,  if  we  push  the  development,  or 
continue  it  too  long,  grow  up,  as  it  were,  all  over  the  plate,  and, 
when  finished,  be  of  too  even  a  tone,  too  much  alike  all  over, 
lacking  in  contrast  ;  if  stopped  short,  it  will  be  lacking  in  inten- 
sity in  the  high  lights,  and,  like  the  under-exposed  plate,  worth- 
less. 

Of  the  two,  under-exposure  or  over-exposure,  the  first-named 
is  the  wrong  side  to  err  on.  If  not  exposed  long  enough  to 
impress  the  image,  no  amount  of  coaxing  will  ever  get  it  out ;  if 
not  there,  you  cannot  get  it.  Over-exposure,  if  not  too  great, 
you  can  control.  If  you  have  reason  to  know  that  a  plate  has 
been  over-exposed,  make  developer  as  before,  with  this  change  : 
use  but  half  as  much  of  the  No.  2  solution,  and  add  half  a  dozen 
drops  of  a  solution  of  the  bromide,  made  up  50  grains  to  the 
ounce  of  water.  The  cutting  down  of  the  No.  2  will  make  the 
development  slower  ;  the  bromide  will  also  restrain  the  rapid 
action,  and  help  to  gain  intensity.  If  it  still  dashes  up,  pour  off 
solution,  add  a  little  more  bromide  ;  if  too  slow,  add  a  little 
more  of  No.  2.  In  this  way  you  may  be  able,  by  judgment  in 
variously  compounding,  save  a  day's  work  that  has  been  over- 
exposed. No  amount  of  writing  can  tell  you  more  than  this  ; 
practice  alone  will  teach  you.  If  a  plate  is  but  little  under- 
exposed it  may  be  saved  by  using  more  of  the  No.  2  ;  if  much 
so,  do  not  bother  with  it,  for,  as  stated,  an  image  not  impressed 
on  the  plate  cannot  be  developed. 

If  at  any  time  a  fog  seems  to  overspread  the  plate,  a  sort  of  a 
veil,  as  it  were,  thrown  over  it,  it  may  be  from  one  of  many 
causes,  among  them  over-exposure,  improper  shade  of  ruby  glass, 
or  light  entering  the  dark-room,  a  camera  or  holders  that  are 
defective,  an  old  and  decomposed  solution  of  No.  1.  Fine  trans- 
7 


parent  lines  on  plate  may  come  from  using  a  brush  to  dust  off 
with  that  has  bristles  that  are  too  stiff,  or  from  injury  to  plate 
in  putting  in  or  taking  out  of  the  holder. 

Spots  may  occur  from  not  breaking  air  bubbles,  or  from  dust 
on  plate.  A  transparent  patch  along  edge  of  plate  is  often  the 
result  of  not  covering  it  with  developer  ;  the  same  careless  act 
will  give  you  a  portion  of  plate  which  varies  in  intensity  and 
detail  from  the  other  parts. 

A  swelling  up,  or  frilling,  as  it  is  termed,  generally  along  the 
edges,  is  the  result  of  using  a  developer  at  too  high  a  temperature. 
It  was  my  intention  to  describe  another  method  of  development, 
that  known  as  the  ferrous  oxalate,  but  upon  considering  the 
matter,  I  think  that  it  is  better  to  confine  this  lesson  to  but  one, 
this  one,  with  modifications,  being  the  best  for  all  work,  giving 
greater  latitude  of  exposure,  better,  therefore,  for  use  by  the 
beginner. 

As  yet,  the  negative  cannot  be  exposed  to  white  light  ;  it  must 
pass  through  the  alum  and  hyposulphite  of  soda  before  it  leaves 
the  dark-room. 


.      CHAUTAUQUA  UNIVERSITY. 

LEWIS  MILLER,  PRESIDENT. 
J.  H.  VINCENT,  CHANCELLOR.  R.  S.  HOLMES,  REGISTRAR. 

He  GDautauqiia  SGtol  of 

SCHOOL    HEADQUARTERS, 
Broome  Street,  New  York. 


CHARLES     WAGER 

Sufi,  of  Instruction,  C.  S.  of  P. 


LESSON    No.    VII. 

Fixing,  Washing,  Drying  and  Varnishing. 

PROCURE  two  half-gallon  glass  jars  with  wide  mouths,  in  one 
make  up  the  alum  solution,  one  part  of  alum  to  eight  or  ten  parts 
of  water  ;  in  the  other,  the  "  hypo "  solution,  one  part  of  the 
hyposulphite  of  soda  to  five  parts  of  water  ;  when  dissolved  and 
thoroughly  mixed  through  the  water,  they  are  ready  for  use;  they 
need  not  be  filtered. 

These  chemicals  you  can  buy  by  the  pound;  they  are  cheap  and 
come  neatly  packed  in  paper  boxes.  For  this  work,  purchase  two 
trays  of  size  known  as  eight  by  ten  inches  and  about  two  inches 
deep  (see  Lesson  III.),  one  to  be  used  for  each  solution  of  which 
pour  enough  in  the  tray  to  fully  cover  the  plate;  if  a  dozen  plates 
are  to  be  passed  through  put  in  larger  quantity  than  for  a  few 
plates  ;  when  through  throw  it  away,  it  is  cheap.  The  "hypo  " 
especially  should  be  renewed  when  it  works  slowly  ;  it  should  do 
its  work,  as  will  be  explained  later,  inside  of  ten  minutes. 

The  negative  having  been  washed  after  development,  as  directed 
in  last  lesson,  it  is  to  be  placed  in  the  alum  solution,  in  which  allow 
it  to  remain  for  four  or  five  minutes  ;  wash  again,  afid  next 
place  in  the  "  hypo  "  solution,  where  it  must  rest  until  all  of  the 
whiteness  has  disappeared,  as  seen  from  the  back,  which  can  be 
determined  by  examining  from  time  to  time.  This  may  be  con- 
ducted in  the  dark  room  with  the  door  open,  in  a  weak  light;  it  is 
not  well  to  trust  to  a  strong  outside  light  until  all  the  whiteness 
has  been  removed  by  the  "  hypo;"  after  this  you  may  expose  it  to 
any  light. 

1 


This  is  known  as  the  process  of  "  fixing."  If  after  taking  the 
negative  from  the  ''  hypo  "  and  examining  it  by  a  strong  light  out- 
side the  dark  room,  you  should  notice  any  brownish-mottled  ap- 
pearance in  looking  through  it,  return  it  to  the  "  hypo  "  until  it  is 
removed.  The  operations  herein  described  do  not  need  any  great 
skill  or  judgment,  they  are  not  as  difficult  to  conduct  as  the  ex- 
posure or  the  development,  yet  simple  as  they  are,  they  need  care 
and. attention,  especially  ''fixing." 

Let  me  again  impress  on  the  attention  of  the  student  the  neces- 
sity of  conducting  this  part  of  the  process  in  a  very  weak  light  ; 
do  not  open  your  dark-room  door  until  plate  has  been  placed  in 
the  hypo;  even  then  my  custom  is  to  cover  the  tray  when  door  is 
opened.  After  it  has  been  in  the  "  hypo "  for  five  minutes  the 
cover  may  be  removed  and  plate  examined  by  looking  at  the 
back,  when  in  most  cases  you  will  notice  a  whitish  cloud  on  a 
portion  of  the  plate  not  yet  dissolved  by  the  action  of  the  "  hypo," 
permit  it,  as  before  stated  to  remain  until  this  has  disappeared. 

Thorough  "fixing,"  as  it  is  termed,  is  all  important ;  on  it  de- 
pends the  life  of  the  negative  ;  if  but  half  done  you  will  some  day 
(it  maybe  a  week  or  months)  discover  a  brownish  stain  on  that 
part  of  the  plate  on  which  the  "  hypo  "  had  not  fully  acted. 

After  the  "  fixing,"  the  plates  are  to  be  placed  in  water  to 
wash;  running  water  if  you  have  it;  if  not,  in  a  large  tub  or  pail 
in  which  the  water  should  be  changed  two  or  three  times  an  hour 
for  several  hours;  if  running  water  is  used,  an  hour  will  be  ample 
time  for  the  washing. 

In  Lesson  HI.  an  illustration  of  the  Scovill  Negative  Washing 
Box  is  seen,  a  cheap  and  effective  apparatus  for  the  purpose. 
Upon  removing  the  plate  from  the  water,  place  in  a  drying  rack, 
or  in  some  way  on  end,  and  allow  it  to  dry  spontaneously. 

If  in  haste,  place  it  in  the  sun 
or  near  the  stove  ;  it  will  not  dry, 
it  will  melt  while  wet,  the  gelatine 
in  the  film,  and  teach  you  the 
lesson  that  will  prevent  its  repeti- 
tion. Many  have  tried  the  experi- 
ment. The  writer  tried  the  sun 
experiment  on  the  first  gelatine 
plate  he  ever  developed  some 
years  ago.  Since  then  he  has  put 

Scovill's  Negative  Drying  Rack,  made     L:C  nlnf-Qc     in   o   rar-L-    lilr»»    frh*»     nne> 
with  either  Wooden  or  Corrugated         HIS  platCS     in  3.  rack    like    the     One 
.       Zinc  Rack.  be,ow  and  waited- 


Next  in  order  is  varnishing. 

The  negative  must  be  absolutely  free  from  all  moisture.  This 
will  be  the  case  on  the  following  day.  If  in  doubt,  hold  near 
the  fire  to  drive  out  all  moisture  for  a  few  moments,  or  stand  in 
the  sun  for  a  while  ;  an  operation  that  may  now  be  performed, 
since  the  water  no  longer  saturates  the  film.  For  amateurs,  I  do 
not  think  it  necessary  to  varnish.  With  care,  scores  of  prints 
may  be  made  from  the  negative  without  damaging  it  in  the 
slightest,  but  for  those  who  may  wish  to  varnish  it  is  well  to  de- 
scribe the  process.  Varnish  can  be  had  especially  for  this  pur- 
pose ;  it  is  known  asScoviirs  Negative  Varnish. 

The  plate  being  dry,  seize  it  by  the  upper  left-hand  corner,  as 
shown  in  the  cut,  holding  it  level  and  pouring  from  bottle  on  to 


the  film  a  small  pool  of  the  varnish  Then  slowly  lower  the  end 
farthest  from  you,  allowing  the  varnish  to  spread  to  the  farther 
end  ;  then  depress  the  upper  edge,  flowing  the  varnish  slowly 
along  to  the  spot  where  your  thumb  is,  then  to  the  corner  next 
to  you,  gradually  raising  until  you  reach  the  following  position  : 


when  the  surplus  is  drained  back  into  the  bottle.  While 
draining  keep  up  a  rocking  motion  to  and  from  you  to  break  up 
any  tendency  of  the  varnish  to  set  in  ridges  ;  cork  bottle  and 

3 


put  plate  in  drying  rack   until  the   varnish  hardens.     This  will 
take  a  couple  of  hours. 

When  a  number  of  negatives  have 
been  developed  and  varnished,  there 
are  two  methods  of  preserving  them 
from  the  dust  and  from  scratches..  One 
is  by  putting  them  in  envelopes  made 
of  stout  paper,  and  called  ''  negative 
preservers,"  which  are  sold  to  corres- 
pond to  different  sized  negatives, 
Another  way  is  by  placing  the  negatives 
in  boxes  like  the  one  shown.  These  are  called  "  negative 
boxes,"  and  are  constructed  to  hold  twenty-four  negatives, 
which  latter  ar,e  slipped  into  the  grooves  at  the  two  sides,  and  thus 
kept  from  rubbing. 


CHAUTAUQUA  UNIVERSITY. 

LEWIS  MILLER,   PRESIDENT. 
J.  H.  VINCENT,  CHANCELLOR.  R.  S.  HOLMES,  REGISTRAR. 


TUG  CWauQiia  Sew  of  Fit 


SCHOOL    HEADQUARTERS, 

•423  Broome  Street,  New  Vork. 


CHARLES     WAGER    HULL, 

Suft.  of  Instruction,  C.  S.  of  P. 


LESSON  No.    VIII. 

INCREASING     AND     REDUCING    INTEN- 
SITY. 

IT  will  sometimes  happen  that  a  negative  will  lack  intensity, 
this  from  causes  not  at  this  time  worth  reciting.  If  you  have  a 
negative  of  a  view  which  you  cannot  easily  retake,  and  which  has 
all  the  needed  detail  in  the  shadows,  then  it  may  be  well  to  try 
some  strengthening  or  intensifying  process  ;  if  you  can  duplicate 
it,  do  so  ;  if  it  has  not  the  requisite  detail,  throw  it  away,  for  all 
the  intensifying  that  can  be  done  will  but  increase  opacity  ;  detail 
you  cannot  add  ;  if  the  image  is  not  upon  the  plate  a  ton  of 
chemicals  will  not  put  it  there.  At  its  best,  the  operation  is  far 
from  being  satisfactory  as  a  rule  ;  an  intensified  negative  is  never 
as  fine  as  would  have  been  the  negative  if  properly  developed.  I 
copy  formula  recommended  by  Cramer ;  in  my  hands  it  has  acted 
as  well  as  any.  Prepare  a  saturated  solution  of  bichloride  of 
mercury  in  water  and  pour  of  this  a  sufficient  quantity  into  a 
solution  of  iodide  of  potassium  (one  and  a  quarter  ounce  of 
iodide  to  six  ounces  of  water),  until  the  point  is  reached,  when 
the  red  precipitate  is  not  dissolved  by  shaking  ;  be  careful  not 
to  add  more  mercury  than  just  enough  to  leave  a  slight  precipi- 
tate. 


To  this  add  one  ounce  of  hyposulphite  of  soda  in  crystals, 
and  add  water  to  make  twenty  ounces. 

For  use,  take  in  proportion  of  one  ounce  of  above  to  three 
ounces  of  water,  in  this  place  plate  to  be  intensified.  Should 
the  plate  not  have  been  well  washed  after  the  "fixing"  pro- 
cess, yellow  stains  will  appear  from  traces  of  hypo  left  in  film. 
Be  careful  not  to  carry  the  operation  too  far  ;  wash  well. 

If  in  the  development  you  have  gone  too  far  and  negative  is 
too  intense,  it  can  be  reduced  by  the  following  : 

Red  prussiate  potash 1  ounce. 

Water 16  ounces. 

Hyposulphite  of  soda 1  ounce. 

Water 16  ounces. 

Pour  out  enough  of  the  hypo  solution  to  cover  plate  ;  to  this 
add,  say,  four  drops  of  potash  solution  to  each  ounce  of  the  hypo 
solution.  Mix  well,  and  in  this  immerse  negative  ;  watch  closely, 
removing  from  time  to  time,  that  you  may  know  how  the  reduc- 
tion proceeds.  When  reduced  sufficiently,  wash  well  and  dry. 

It  is  better  in  developing  to  err  on  side  of  too  great  intensity 
and  then  reduce,  than  to  stop  short  in  development  and  endeavor 
to  intensify.  The  first  will  prove  a  success  ;  the  last,  as  a  rule, 
will  prove  a  failure. 


FAILURES. 

Wi  i  HOUT  failures  there  would  be  nothing  by  which  to  measure 
success  ;  we  must  make  them,  and  note  how  we  made  them,  that 
we  may  in  future  avoid  them  ;  they  are  valuable  just  in  the  ratio 
that  we  discover  and  note  the  cause. 

It  is  always  well  to  know  that  which  should  not  be  done,  as  well 
as  to  know  that  which  should  be  done.  Among  the  most  common 
causes  of  failure  are  the  following  : 

Transparent  Spots  :  dust  on  the  plate  from  dirty  holders  or 
camera,  air  bubbles  on  plate  during  development ;  sometimes 
from  "  hypo,"  which,  falling  on  the  floor,  has  been  ground  into 
fine  powder,  and,  floating  in  the  air,  settled  on  the  plate  ;  keep 
holders,  camera  and  dark  room  clean  ;  dust  plate  before  exposure, 
and  before  development 

Opaque  Spots,  either  from  an  imperfect  plate  or  developing 
solutions  improperly  made  and  filtered. 


Lines  Across  Plate,  from  dusting  with  brush  having  coarse 
hair  in  it,  and  from  sliding  plate  into  or  out  of  holder. 

Weak  Negatives,  with  plenty  of  detail  in  shadows:  over-expo- 
sure; less  time  and  longer  development  will  increase  the  intensity. 

Too  much  Intensity  in  High  Lights  without  detail  in  shadows  : 
unde  -exposure  ;  give  time  enough  to  impress  detail  on  plate  ; 
stop  development  before  negative  becomes  too  black  in  high 
lights. 

Foggy  Negatives.  By  this  term  is  meant,  a  veiled  appearance, 
which  dulls  the  brilliancy  of  the  negative  ;  due  to  light  of  the 
wrong  kind  in  dark  room,  holder,  and  camera,  during  development, 
or  before  it  has  been  "fixed."  Examine  each  with  care;  find  it 
you  must ;  good  work  cannot  be  made  until  you  do.  Using 
"hypo  "  tray  to  develop  in  ;  old  decomposed  pyrogallic  solution; 
these  will  cause  a  stain  to  cover  the  plate  which  might  be  mis- 
taken for  fog. 

Crystallizations  on  Negative  are  due  to  imperfect  washing  out 
of  the  "hypo  "  after  the  "  fixing,"  and  so  are  brown  stains. 

Frilling.  This  is  due  to  the  swelling  and  bulging  up  of  the 
film  during  development.  Keep  solutions  below  70  deg.  Fahr.; 
it  may  occur  during  washing  if  water  is  too  warm  (over  80  deg.), 
and  by  remaining  too  long  in  water. 

The  alum  solution  after  developing  will  generally  prevent  this 
trouble  if  developer  is  kept  below  70  deg.  Fahr. 

We  have  now  traveled  together  over  the  photographic  road 
from  beginning  to  end,  so  far  as  the  work  of  making  the  negative 
is  concerned.  The  story  has  been  told  in  as  plain  a  way  as  the 
writer  can  tell  it  ;  more  detail  has  been  entered  into  than  usual ; 
methods  have  been  described  so  fully  that  those  who  know  noth- 
ing of  the  art  can  understand,  at  least  such  has  been  the  effort. 
Confusing  formulas  have  been  avoided;  methods  only  have  been 
given  which  will  produce  good  work.  Speculations,  theories,  and 
experiments  have  been  left  for  the  student  to  work  over  after  he 
has  learned  how  to  make  a  picture  ;  if  that  which  has  been  written 
is  followed,  success  must  and  will  be  the  result.  Then,  and  not 
until  then,  try  other  formulas,  after  which  most  of  my  readers  will 
be  glad  to  return  to  the  plain  ABC  sort  of  formula  herein  given, 
and  leave  to  others  the  entangling  formulas  that  are  suggested 
without  reason  and  used  because  somebody  told  you  so. 


CHAUTAUQUA    UNIVERSITY. 

LEWIS  MILLER,  PRESIDENT. 
J.  H.  VINCENT,  CHANCELLOR.  R.  S.  HOLMES,  REGISTRAR. 


He  Giaiitaiupia  Sctooi  of 


SCHOOL    HEADQUARTERS, 

4=23  Broome  Street,  New  York:. 


CHARLES     WAGER    HULL, 

Supt.  of  Instruction,  C.  S.  of  P. 


LESSON   No.   IX. 


PRINTING  ON  ALrBITMENIZED  PAPER. 

THE  SILVER  SOLUTION. 

THE  albumen  paper  that  is  sold  by  dealers  has  been  soaked  in 
an  alkaline  salt,  and  when  such  paper  is  floated  upon  a  solution 
of  silver  nitrate,  two  compounds  are  formed;  the  organic  albumi- 
nate  of  silver  and  silver  chloride,  both  of  which  are  sensitive  to 
light. 

A  sixty-grain  solution  of  silver  nitrate  is  to  be  recommended, 
that  is,  one  that  contains  sixty  grains  of  silver  to  the  ounce,  al- 
though a  much  weaker  one  will  answer  the  purpose  tolerably 
well.  As  a  matter  of  course  the  bath  grows  weaker  with  use. 

Such  a  bath  may  be  made  as  follows  : 

Water 64  ounces. 

Silver  nitrate 8 

Ammonic  nitrate 2        " 

Magnesic  nitrate 1  ounce. 

To  each  ounce  of  the  solution  add  one  drop  of  strong  ammonia. 
By  adding  silver  nitrate  from  time  to  time  this  solution  may 
be  kept  up  to  the  required  standard.  This  may  be  ascertained 
by  the  argentometer;  the  figures  at  the  surface  of  the  bath  in 
which  the  instrument  is  floating  indicating  the  number  of  grains 
per  ounce.  The  ordinary  hydrometer  will  serve  well  enough,  since 
we  may  add  silver  from  time  to  time  in  sufficient  quantity  to  keep 


the  instrument  at  the  same  level  when  floated  in  the  bath.  We 
may  indeed  employ  any  glass  tube  closed  at  one  end  and  open  at 
the  other.  Cause  the  tube  to  stand  upright  in  the  liquid  by  drop- 
ping shot  into  the  open  end.  The  surface  of  the  bath  may  be 
marked  by  a  ring  of  thread,  and  this  mark  may  afterward  be  made 
permanent  by  a  three-cornered  file.  Of  course  the  tube  must  al- 
ways contain  shot  of  the  same  number  and  size. 

On  account  of  the -presence  of  ammonic  and  magnesic  salts,  the 
argentometer  should  read  not  sixty  but  eighty.  Only  silver  ni- 
trate needs  to  be  added  from  time  to  time,  as  the  solution  is  not 
depleted  of  the  alkaline  salts,  except  as  the  quantity  of  the  liquid 
is  diminished.  The  best  way  is  to  add  a  quantity  of  solution 
compounded  as  above,  and  then  add  silver  nitrate  to  bring  the 
whole  up  to  the  required  reading  on  the  hydrometer. 

The  silver  bath  should  be  kept  in  an  alkaline  condition  by  add- 
ing, occasionally,  a  few  drops  of  ammonia.  The  tendency  to  be- 
come acid  is  due  to  the  liberation  of  nitric  acid  from  the  silver 
nitrate. 

During  the  floating  of  the  paper  some  organic  particles  pass 
from  the  paper  into  the  bath,  when  they  soon  decompose  and 
discolor  the  solution.  The  bath  may  be  cleared  by  shaking  it  up 
with  a  handful  of  china  clay  or  kaolin,  which  adheres  to  the  par- 
ticles and  carries  them  to  the  bottom.  The  bath  may  then  be  fil- 
tered, or,  when  used,  it  may  be  decanted,  leaving  the  sediment 
behind.  Or,  better  yet,  the  bath  may  be  drawn  from  the  bottle 
by  two  tubes,  carried  in  one  cork  after  the  manner  of  the  wash 
bottle  that  is  much  used  in  laboratories.  One  tube  is  a  syphon 
that  reaches  to  the  bottom  of  the  bottle,  while  the  longer  arm  is 
outside  the  bottle  and  carries  the  solution  into  the  tray.  The 
other  tube  passes  merely  through  the  cork,  and  through  this  a 
current  of  air  is  blown,  the  pressure  from  which  starts  the 
syphon. 

FLOATING  THE  PAPER. 

This  must  be  done  in  a  glass,  porcelain  or  wooden  tray.  If 
wood  is  used,  the  bottom  and  sides  should  be  well  shellacked.  A 
convenient  tray  for  amateurs  is  the  "  Waterbury  "  tray,  of  a  size 
large  enough  to  float  a  half  sheet  at  a  time. 

Lift  the  sheet  to  be  floated  by  two  opposite  corners,  with  the 
film  side  down,  and  let  it  touch  the  bath  first  near  one  end. 
Lower  the  rest  of  the  sheet  smoothly  and  quickly  until  it  all  rests 
upon  the  bath.  Across  each  end  lay  a  light  piece  of  wood,  until 

2 


the  curling  of  the  edges  has  ceased.  These  edges  may  easily  be 
kept  down  by  breathing  upon  them.  As  soon  as  possible,  each 
corner  of  the  sheet  should  be  lifted  and  bubbles  of  air  adhering 
to  the  film  should  be  broken  with  a  glass  rod,  or  blown  away  by 
a  smart  current  of  breath.  No  drops  of  the  solution  should  be 
spattered  upon  the  top  of  the  sheet.  The  albumen  paper  com- 
monly sold  in  the  market  should  be  floated  about  two  minutes  in 
winter,  and  a  minute  and  a  quarter  or  a  minute  and  a  half  in 
summer.  For  printing  with  weak  negatives,  the  floating  should 
be  somewhat  longer. 

Withdraw  the  sheet  by  grasping  two  corners  with  wooden  clips 
and  hold  it  over  the  bath  to  drain.  It  is  an  excellent  plan  to 
draw  the  sheet  over  a  glass  rod  fixed  across  one  end  of  the  tray. 
This  scoops  all  superficially  adhering  silver  back  into  the  bath. 
The  sheet  may  now  be  pressed  between  sheets  of  blotting  paper 
and  hung  up  to  dry,  being  hung  by  the  clips  to  stretched  twine 
or  across  wooden  rods.  The  drying  should  of  course  take  place 
in  the  darkness,  or  in  extremely  weak  light. 

The  albumenized  side  of  the  paper,  either  before  or  after  sen- 
sitizing, should  not  be  handled  more  than  is  absolutely  necessary 
in  cutting  it  to  proper  size.  The  hands  should  be  clean  and  dry. 
The  sensitized  paper  soon  becomes  discolored  and  is  seldom  in 
its  best  condition  after  twenty-four  hours.  In  cold,  dry  weather, 
however,  it  will  keep  well  for  several  days. 

PRINTING  ON  ALBUMEN  PAPER. 

The  word  "  printing,"  as  used  in  Photography,  is  a  misnomer. 
The  word,  as  seen  in  its  etymology,  means,  properly,  to  take 
an  impression  by  some  mechanical  means.  But  photographic 
"  printing  "  is  a  process  of  reproduction  by  a  chemical  change 
that  is  effected  in  a  sensitized  surface  through  the  agency  of  light ; 
and  might  therefore  be  more  properly  styled  "  copying,"  after  the 
manner  of  the  Germans.  The  only  mechanical  changes  involved 
are  such  as  serve  to  bring  the  sensitive  surface  into  proper  rela- 
tion to  the  actinic  power  of  the  light. 

FUMING. 

The  sensitized  paper,  after  being  thoroughly  dried,  by  artificial 
heat  or  otherwise,  should,  before  printing,  be  exposed  for  a  time 
to  the  fumes  of  ammonia.  The  ammonia  is  useful  in  absorbing 
the  free  chlorine  that  is  evolved  during  the  exposure  of  the  paper 


to  the  sunlight.  To  this  end,  secure  an  old  box  that  is  two  or 
three  feet  long  and  half  as  wide  and  deep.  Paste  black  or  brown 
paper  over  the  cracks  and  set  the  box  on  end.  The  front  should 
be  removable,  and  might  conveniently  work  with  a  hinge.  It 
should  fit  pretty  accurately,  and  around  the  margins  it  would  be 
well  to  tack  a  strip  of  cloth.  Instead  of  this  wooden  front,  a 
large  piece  of  pasteboard  or  blotting  paper  might  be  used,  it 
being  crowded  in  at  the  edges  and  the  whole  box  then  covered 
with  a  cloth. 

Provide  the  box  with  a  false  bottom  placed  about  two  inches 
above  the  real  one.  This  may  consist  of  a  porous  cloth  stretched 
across,  or  of  a  perforated  thin  board  or  pasteboard.  The  perfor- 
ations should  be  numerous. 

The  paper  is  placed  in  the  box  by  putting  two  sheets  back  to 
back  and  hanging  them,  by  means  of  clips  provided  with  hooks, 
to  twine  stretched  back  and  forth  across  the  top  of  the  box  ;  or, 
the  sheets,  back  to  back,  may  be  pinned  through  the  corners  to 
the  sides  and  top  of  the  box.  A  large  number  of  sheets  may  be 
fumed  at  one  time.  When  all  are  in  place,  put  a  shallow  tray  or  plate 
containing  strong  ammonia  under  the  perforated  bottom,  and 
close  the  front.  The  paper  should  fume  about  fifteen  minutes  in 
warm  weather  and  nearly  double  the  time  in  cold  weather.  After 
fuming,  a  short  time  should  elapse  before  printing,  to  allow  the 
paper  that  is  moist  with  the  fumes  of  ammonia  to  contract  and 
resume  its  normal  size. 

THE  PRINTING  FRAME. 

A  frame  that  is  at  least  one  size  larger  than  the  negatives  to  be 
printed  from  is  a  great  convenience.  In  the  first  place,  in  the 
larger  frame  the  negative  will  be  printed  to  the  very  margins  ; 
and  in  the  second  place,  the  larger  frame  will  be  a  great  help  if 
you  desire  to  vignette  upon  your  print  clouds  from  another  nega- 
tive. A  clear  glass  plate  of  the  same  size  as  the  frame  may  be 
used  to  support  the  smaller  negative. 

Place  the  negative  in  the  frame,  film  up,  and  upon  it  lay  the 
paper  with  the  sensitive  surface  down,  that  is,  next  to  the  nega- 
tive. Put  the  back  of  the  frame  in  its  place  and  press  it  down 
with  the  springs.  The  frame  is  now  ready  to  be  exposed  to  the 
light. 

THE  EXPOSURE. 

The  change  effected  by  the  light  in  the  sensitive  film  may  be 
expressed  by  the  formula  : 

Ag  Cl  +  sunlight  =  Ag  +  Cl. 
4 


We  see  that  free  chlorine  is  evolved  and  metallic  silver  depos- 
ited. It  is  this  fine  deposit  of  silver  that  constitutes,  by  its 
greater  or  less  amount,  the  lights  and  shadows  of  the  picture. 

If  the  negative  is  very  weak  and  flat,  that  is,  lacking  in  con- 
trast, it  were  better  not  to  print  by  direct  sunlight ;  otherwise 
the  exposure  may  be  made  to  the  direct  rays  of  the  sun.  To 
effect  this,  a  wide  board  may  be  thrust  out  of  a  window  having  a 
southern  exposure.  It  is  better  yet,  however,  to  nail  together  three 
boards  in  the  form  of  a  right  angle  triangle,  and  so  place  the  tri- 
angle in  the  open  window  that  the  hypothenuse  should  be  perpen- 
dicular to  the  line  of  the  sun's  rays.  Strips  may  be  nailed  across 
the  board  for  supporting  the  printing  frame. 

The  progress  of  the  printing  must  be  carefully  watched.  With- 
draw the  frame  from  time  to  time  into  the  diffused  light  of  the 
room,  slip  the  spring,  raise  one  end  of  the  back,  and  examine  the 
print.  The  print  when  ready  to  be  taken  out  should  be  consider- 
ably darker  than  the  finished  picture  is  to  be.  This  excess  of 
blackness  will  disappear  in  the  subsequent  washing  and  fixing. 
Rather  weak  and  flat  negatives  should  be  printed  especially  dark, 
as  they  lose  more  of  their  depth  in  subsequent  operations.  Exper- 
ience alone  will  determine  just  how  long  to  continue  the  exposure 
in  order  to  secure  the  best  results. 

WASHING  THE  PRINTS. 

The  washing  may  be  performed  in  a  japanned  or  porcelain 
tray.  Lay  the  prints  one  by  one  face  down  into  the  tray  and 
press  them  beneath  the  water.  Twenty-five  or  thirty  may  be 
washed  at  a  time.  After  being  placed  in  the  tray  they  should  be 
moved  by  slipping  them  from  the  bottom  and  placing  them  upon 
the  top.  After  standing  eight  or  ten  minutes  the  water  may  be 
poured  off  and  a  fresh  supply  added.  The  same  manipulation 
should  be  performed  with  each  washing  as  with  the  first.  Into 
the  fourth  wash,  a  quarter  of  an  ounce  of  saturated  solution  of 
sodic  bicarbonate  and  half  an  ounce  of  saturated  solution  of  com- 
mon salt  may  be  placed.  The  soda  will  bring  the  prints  into  an 
alkaline  condition  that  is  favorable  to  the  action  of  the  toning 
bath.  The  prints  should  remain  in  this  mixture  not  more  than 
five  minutes,  and  should  then  be  well  rinsed.  They  are  now 
ready  for  the 

TONING  BATH. 

The  office  of  the  gold  toning  bath  is  to  substitute  for  the  red- 
dish, disagreeable  color  of  the  print  a  bluish  or  brownish  black. 


The  chemical  change  involved  is  not  at  present  very  well  under- 
stood 

It  is  a  prime  requisite  of  any  toning  bath  that  it  be  slightly,  but 
decidedly  alkaline.  It  should  be  tested  from  time  to  time  with 
litmus  paper,  especially  if  it  does  not  act  properly. 

Many  toning  baths  are  in  use  and  they  differ  somewhat  in 
results.  I  will  describe  one  or  two. 

STOCK  SOLUTION. 

Water 15  ounces. 

Chloride  of  gold  and  sodium 15  grains. 

To  make  up  a  toning  bath  for  twenty  prints,  take 

Water 10  ounces. 

Sodic  bicarbonate 3  grains. 

Sodic  chloride  (common  salt) 6         " 

Stock  solution  of  gold 3  ounces. 

A  good  pinch  of  sodic  bicarbonate  and  of  sodic  chloride  will 
be  sufficiently  accurate.  To  this  bath  add  three  ounces  of  the 
stock  solution  cf  gold  that  has  first  received  three  drops  of  a 
saturated  solution  of  bicarbonate  of  soda.  This  last  is  to  main- 
tain the  alkalinity  of  the  bath. 

Another  excellent  toning  bath  is  as  follows : 

STOCK  SOLUTION. 

Water 13  ounces. 

Chloride  of  gold  and  sodium 15  grains. 

Pour  three  ounces  of  the  stock  solution  into  the  toning  tray 
and  render  it  slightly  alkaline  by  carefully  adding  a  saturated 
solution  of  sodic  bicarbonate.  Then  add  a  pint  of  water  and 
about  twenty  grains  of  sodic  acetate.  After  standing  half  an 
hour  this  bath  will  be  ready  for  use. 

Lay  the  prints  in  the  bath  one  by  one,  face  down,  and  move 
them  continually,  so  as  to  avoid  sticking  together  of  the  prints, 
and  consequent  unevenness  of  tone.  Ten  or  twelve  may  be 
toned  at  one  time,  and  as  these  are  taken  out,  others  may  be 
added.  If  the  bath  becomes  very  weak  and  slow  in  its  action, 
provided  excessive  cold  be  not  the  cause,  more  gold  should  be 
added. 

In  ten  or  fifteen  minutes  the  reddish  color  should  begin  to  dis- 
appear and  be  gradually  succeeded  by  a  rich  purplish  black  in 
the  shadows.  The  prints  should  not  be  withdrawn  from  the  bath 

6 


until  this  stage  has  been  reached.     On  the  other  hand,  they 
should  never  lie  so  long  as  to  acquire  a  bluish  or  slaty  color. 

As  heat  accelerates  chemical  action,  it  is  important  that  the 
bath  be  kept  at  about  the  same  temperature  as  the  room,  sixty- 
five  or  sixty-six  degrees.  To  effect  this  the  toning  tray  may  be 
set  on  a  hot  soapstone  ;  or  better  yet,  as  some  one  has  suggested, 
the  tray  may  be  set  across  a  small  open  cask  in  the  bottom  of 
which  stands  a  burning  lump.  The  bath  must  not  be  overheated. 
The  prints  must  be  examined  in  strong  enough  light  to  enable 
the  operator  to  judge  accurately  of  the  tone.  After  thorough 
rinsing  the  prints  are  ready  for  the 


FIXING    BATH. 

The  office  of  the  fixing  bath  is  to  dissolve  the  silver  chloride 
not  acted  upon  by  light  ;  without  which,  the  picture  is  subjectto 
further  light-action,  will  consequently  not  retain  brilliancy  and 
definition,  and  will  in  fact  assume  color  all  over. 

One  of  the  products  of  the  fixing  process  is  a  double  salt,  the 
argento-sodic  hyposulphite,  which  is  again  soluble  in  an  excess  of 
sodium  hyposulphite,  and  must  be  totally  removed  from  the 
print  by  subsequent  washing,  to  secure  its  perfect  permanency.  - 

The  following  bath  is  recommended  : 

Water.    1  gallon. 

Sodic  hyposulphite 1  pound. 

Sodic  bicarbonate 1  tablespoonfui. 

Common  salt 1 

The  prints  should  be  placed  in  the  bath  one  by  one,  enough  of 
the  liquid  being  used  to  cover  them  well.  Move  them  frequently, 
as  in  toning,  to  prevent  sticking  together.  They  should  lie  in  the 
bath  not  less  than  fifteen  minutes.  It  is  better  to  prolong  the 
time  to  twenty  minutes,  if  the  bath  is  rather  cool.  The  bath 
should  be  made  up  some  hours  or  days  beforehand,  as  the  dis- 
solving of  the  crystals  lowers  the  temperature  materially.  The 
fixing  bath  should  be  thrown  away  after  once  using.  The  fixing 
tray  should,  under  no  circumstances,  be  used  for  any  other 
purpose. 

To  insure   against  blistering,  it  is  well  to  transfer  the  prints* 
from  the  fixing  bath  into  a  strong  solution  of  common  salt,  in 
which  they  may  lie  three  or  four  minutes. 


They  are  then  ready  for 


WASHING. 


A  limited  number  may  be  washed  well  enough  in  a  tray.  Rock 
the  tray  occasionally  or  move  them  by  continually  slipping  out 
the  bottom  one  and  placing  it  upon  the  top.  The  water  should 
be  changed  seven  or  eight  times,  and  during  the  earlier  part  of 
the  process  the  changes  should  be  more  frequent  than  during 
the  latter  part.  A  thorough  elimination  of  the  fixing  solution  is 
essential  to  the  permanence  of  the  photograph.  There  is  little 
danger,  therefore,  of  continuing  the  washing  too  long.  Some 
even  allow  water  to  run  over  the  prints  all  night.  It  is  supposed 
by  many,  however,  that  an  excessively  prolonged  soaking  in 
water  weakens  the  print. 

The  object  of  washing  the  print  is  to  remove  from  it  all  sodic 
hyposulphite  and  the  derivatives  of  the  fixing  process.  A  test 
for  perfect  elimination  is  .the  iodide  of  starch  paper  of  dark  pur- 
ple color,  which,  when  brought  in  contact  with  prints,  or  the  water 
dripping  from  them,  will  bleach  immediately  if  only  a  trace  of 
hyposulphate  be  present. 

To  remove  these  last  traces  of  the  obnoxious  salt,  a  tablespoon- 
ful  of  Flandreau's  S.  P.  C.  Hypo  Eliminator,  added  to  one 
quart  of  the  last  washing  water,  and  allowing  the  prints  to  re- 
main therein  for  a  few  moments,  and  then  rinsing  them  off  again 
with  pure  water,  will  effect  a  thorough  elimination,  without  which 
albumenized  paper  prints  will  always  be  liable  to  turn  yellow  or 
to  fade. 

The  eliminator  should  not  be  used  in  large  proportions,  as  by 
too  strong  solutions  the  whole  silver  deposit  might  suffer. 


CHAUTAUQUA  UNIVERSITY. 

LEWIS  MILLER,  PRESIDENT. 
J.  H.  VINCENT,  CHANCELLOR.  R.  S.  HOLMES,  REGISTRAR. 


THE 


Ciljautaiiqiia  j&jool  of  photograph), 

SCHOOL    HEADQUARTERS, 

423  Broome  Street,  New  York. 

CHARLES     WAGER     HULL, 

Supt.  of  Instruction,  C.  S.  of  P. 


LESSON   No.   X. 

Printing    on    Ready-Sensitizefl    Albumen 
Paper. 

WE  have  been  told  in  the  previous  lesson  how  to  sensitize  al- 
bumen paper,  how  to  print  upon  it,  and  how  to  tone  and  fix  prints 
which  have  been  made  upon  it. 

For  the  convenience  of  professional  photographers  as  well  as 
that  of  amateurs,  a  brand  of  paper  albumenized  and  sensitized  in 
the  solution  of  nitrate  of  silver,  quite  ready  for  printing,  is  now  in 
the  market,  and  extensively  used.  This  paper,  being  capable  of 
giving  universally  good  results,  exempts  the  operator  from  an- 
noyances often  encountered  when  silvering  paper,  is  of  especial 
value  to  the  student,  and  our  undivided  attention  should  there- 
fore be  given  to  the  mode  of  working  with  it. 

We  have  learned  how  to  sensitize  albumenized  paper,  and  how 
to  fume  it  in  the  vapors  of  ammonia  preparatory  to  printing. 
With  the  paper  before  us,  the  first  operation  is  dispensed  with; 
the  second,  however,  becomes  an  absolute  necessity. 

Before  we  advance  any  further,  it  is  interesting  to  examine  the 
reasons  by  which  the  photo-chemist  has  been  induced  to  prepare 
ready-sensitized  paper,  and  how  it  is  done.  The  sensitive  paper 
prepared  in  our  own  laboratories;  notwithstanding  its  otherwise 
excellent  qualities,  does  not  keep  in  good  working  condition  for 
a  length  of  time,  in  fact  through  the  influence  of  such  adverse 
circumstances  as  heat,  moisture  in  the  atmosphere,  or  air 
tainted  with  certain  gases,  it  will  lose  its  brilliant  whiteness,  as- 
sume a  yellowish  tint,  and  will  finally  turn  to  a  brown  color, 
and  thus  become  unfit  for  photographic  printing.  The  theories 
upon  which  these  changes  are  based,  as  well  as  those  explaining 
the  other  processes  connected  with  printing,  we  will  consider  in 
a  future  lesson;  be  it  sufficient  to  say  that  the  desire  to  obtain  a 
more  durable  sensitive  paper  has  resulted  in  the  ready-sensitized 
paper  before  us. 


When  floating  a  sheet  of  salted  and  albumenized  paper  upon 
silver  solution,  the  chloride  in  the  albumen  film  converts  the  silver 
nitrate  to  a  chloride,  the  decomposition  of  which  substance,  by 
light,  gives  us  the  photographic  picture.  When  removing  the 
sheet  from  the  silver  bath,  much  of  the  solution  adheres  to  the 
paper,  dries  there,  and  assists  afterwards  considerably  to  make 
the  print.  This  same  silver  prevents  the  paper  from  being  durable 
or  retaining  its  whiteness,  and  must  be  removed  unless  the  paper 
be  used  the  same  day.  This  is  done  by  washing  it  in  water  after 
the  chlorification  has  been  thoroughly  effected.  In  that  state 
we  have  upon  the  sheet  a  film  of  the  organic  silver  albuminate, 
finely  interspersed  with  silver  chloride.  To  prevent  a  decomposi- 
tion of  these  bodies  by  atmospheric  influences  or  high  tempera- 
ture, the  back  of  the  paper  is  coated  with  other  chemicals  like 
citric  acid,  citrates,  nitrites,  sulphites,  and  carbonated  alkalis ; 
the  latter  being  probably  the  most  effective  of  all.  Without  this 
precaution  the  washing  away  of  the  excess  of  nitrate  of  silver, 
would  be  of  no  benefit  to  the  paper,  and  it  would  be  likely  to 
turn  color  in  time. 

The  ready-sensitized  paper  of  commerce,  as  we  purchase  it  from 
the  dealer,  may  possibly  give  under  a  very  strong  and  dense  nega- 
tive a  tolerable  good  print,  but  to  secure  good  impressions  from 
comparatively  feeble  negatives,  it  is  absolutely  necessary  to  fume 
it  in  the  vapors  of  ammonia.  The  effects  produced  by  fuming, 
cannot  be  the  same,  as  upon  unwashed  paper,  as  without  the 
presence  of  free  nitrate  of  silver,  the  respective  combination  can- 
not form,  and  the  ammonia  will  act  here  only  as  an  absorber  of 
the  chlorine  gas,  which,  during  printing,  is  liberated  from  the 
chloride  of  silver  by  the  action  of  light. 

The  great  amount  of  acid  matter  employed  to  make  the  paper 
durable,  requires  the  aid  of  alkalis  to  establish  that  state  of  neu- 
trality requisite  in  printing  upon  albumenized  paper.  Hence  we 
will  understand  how  fuming  assists  to  gain  the  desired  result,  and 
the  importance  of  fuming  ready-sensitized  paper  cannot  be  too 
forcibly  impressed  upon  the  mind  of  the  student. 

If  printed  copies  are  well  preserved  from  humid  air,  toning  may 
be  deferred  to  a  convenient  time  or  till  a  sufficient  number  of 
prints  has  accumulated. 

Toning,  Fixing  and  Washing 

Does  not  differ  from  the  processes  described  before,  but  it  will 
be  interesting  to  all  if  we  describe  the  toning  bath,  which  has  been 


worked  with  good  success  in  the  practicing  class  of  the  Chautau- 
qua  School,  and  by  which  equally  good  prints  have  been  made 
upon  ready-sensitized  and  freshly-prepared  albumen  paper. 

The  washing  of  the  prints  before  toning  should  be  conducted 
with  all  possible  care  and  attention.  It  is  done  either  by  subject- 
ing them,  for  at  least  fifteen  minutes,  to  a  continuous  stream  of 
water,  or  to  a  half-a-dozen  of  changes  of  water  in  intervals  of  ten 
minutes.  If  towards  the  end  of  washing  a  slight  amount  of  al- 
ktaline,  say  ordinary  washing  soda  be  added,  the  prints  will  be 
better  disposed  to  receive  the  gold  of  the  toning  bath. 

As  a  rule,  ready-sensitized  paper  requires  but  a  very  slight  over- 
printing, Long  continued  toning,  possibly  with  a  view  to  bleach 
out  prints  when  too  dark,  is  detrimental  to  the  general  tone  ;  it 
turns  the  whites  to  a  sickly  grey,  depriving  the  print  of  its 
brilliancy. 

After  sufficient  washing,  toning  can  be  commenced.  The  gold 
bath,  to  which  experts  have  given  the  name  "  Chautauqua  Toning 
Bath,"  is  prepared  about  thirty  minutes  before  use,  and  is  as 
follows  : 

Make  a  stock  solution  of  fifteen  grains  of  chloride  of  gold  and 
sodium  in  fifteen  ounces  of  water,  of  which  two  ounces  are 
poured  into  the  toning  tray  ;  best  of  a  light  material,  porcelain 
or  white  agate  ware. 

Chloride  of  gold  reacts  acid,  but  as  it  does  not  tone  in  that 
condition,  it  must  be  rendered  neutral  or  slightly  alkaline.  Test 
with  blue  litmus  paper;  acidity  changes  the  color  to  red,  alkalines 
restore  the  blue.  Neutralize  the  acid  gold  solution  by  adding 
gradually,  in  small  portions,  a  saturated  solution  of  bicarbonate 
of  soda,  till  the  bluing  of  the  litmus  test  paper  indicates  neutrality. 
When  in  that  state,  ten  grains  of  acetate  of  soda  are  added,  and 
when  dissolved  the  solution  must  be  diluted  with  not  less  than 
eighteen  ounces  of  water,  before  prints  can  be  subjected  to  its 
action. 

No  further  remarks  are  necessary,  all  manipulations  and  phen- 
omena appearing  during  toning  are  alike  with  those  of  freshly 
prepared  paper. 

Fixing,  washing  and  hypo  elimination  are  likewise  the  same. 

Printing  on  Plain  Paper. 

The  term  "  plain  paper"  signifies  photographic  positive  paper, 
as  it  comes  direct  from  the  paper  mills,  without  having  under- 


gone  preparation  for  future  use,  as  salting,  albumenizing  or  extra 
sizing. 

If  photographs  on  paper  are  to  be  finely  finished  in  aquarell, 
sepia,  india  ink  or  similar  pigments,  albumenized  or  otherwise 
prepared  surfaces  present  to  the  artist  a  variety  of  difficulties, 
among  which  stands  foremost  its  gloss  and  hardness,  repelling 
the  aqueous  mixture  of  color  substances  to  such  an  extent  as  to 
make  it  extremely  difficult,  even  impossible  in  some  cases,  to 
wash  in  large  surfaces,  to  blend  colors  into  each  other,  or  to 
build  up  intensity  by  repeated  application  of  tones.  Non-albu- 
menized  paper  is  therefore  more  pleasing  to  the  artist,  to  whom 
the  photograph  serves  as  a  sketch  or  base  to  work  upon,  and  is 
much  used  by  landscape,  still-life  and  portrait  artists. 

Plain  paper  is  also  absolutely  necessary  when  photographic 
half  tones  are  to  be  reduced  into  a  system  of  lines,  stipple  or 
cross  hatchings  for  reproductions  in  high  relief  for  mechanical 
printing  methods,  for  a  variety  of  transfers,  and  the  photographic 
tracing  processes,  which  will  be  considered  further  on. 

Plain  paper  is,  of  course,  subjected  to  somewhat  different 
treatment  than  our  old  friend  the  albumenized  paper,  and  of  the 
great  variety  of  methods  practiced,  we  will  select  two  which 
have  been  generally  approved  of  by  professional  photographers. 

No.  1.  A. — Make  a  solution  of  300  grains  of  chloride  of  am- 
monium in  one  gallon  of  water,  and  soak  the  paper  in  it  for  a 
minute  or  two,  being  careful  to  avoid  air  bubbles  forming  and 
settling  upon  the  surface.  Then  hang  up  and  dry. 

B. — Dissolve  one  and  a  half  ounce  of  crystallized  nitrate  of 
silver  in  fifteen  ounces  of  soft  or  distilled  water.  Divide  the 
solution  into  three  parts  ;  set  one  of  them  aside,  and  add  to  the 
two-thirds  aqua  ammonia  fortior  till  the  yellowish  brown  precipi- 
tate formed  is  redissolved  in  an  excess  of  the  precipitant,  being 
careful  to  add  only  enough  ammonia  to  render  the  solution  per- 
fectly clear  again,  and  without  exhibiting  more  than  only  a  per- 
ceptible odor.  To  this  ammonio-nitrate  of  silver  solution  add 
the  third  of  the  original  solution  set  aside,  which  will  cause  a 
strong  turbition  of  the  liquid,  but  which  will  vanish  by  the  ad- 
dition of  a  few  drops  of  glacial  acetic  acid.  Then  filter. 

The  salted  paper  may  be  floated  upon  this  solution  for  two  or 
three  minutes,  or  what  is  preferred  by  most  practitioners,  the 
solution  is  spread  over  the  paper,  fastened  with  pins  upon  a 
clean  board,  either  with  a  tuft  of  clean  cotton  wool,  or  a  Buckle's 
brush.  After  the  paper  has  been  thoroughly  sensitized  and  dried 


in  the  dark  room,  it  may  be  cut  to  the  required  sizes  and  printed 
upon  in  the  usual  way. 

Plain  paper  had  best  be  toned  and  fixed  in  one  operation,  to 
secure  vigorous  and  brilliant  prints. 

Dissolve  fifteen  grains  of  pure  terchloride  of  gold  in  seven 
and  a  half  ounces  of  distilled  water,  and  add  it  drop  by  drop  and 
by  constant  stirring  up  to  a  solution  of  two  ounces  of  hyposulphite 
of  soda  in  twelve  ounces  of  distilled  water.  If  properly  prepared 
the  solution  remains  perfectly  clear  and  limped  ;  if  brown  or 
yellow  it  is  unfit  for  use. 

Of  this  gold  stock  solution  add  three  ounces  to  fifteen  ounces 
of  a  ten  percent,  hypo  solution  and  mix  well.  Prints  without  a 
previous  washing  are  immersed  therein.  It  fixes  and  tones 
simultaneously,  although  it  requires  a  much  longer  time  to  ob- 
tain neutral  or  black  tones.  Plain  paper  prints  have  shown  with 
this  method  a  great  durability. 

No.  2. — A  printing  method  upon  plain  paper  was  given  by 
Mr.  Hardwich  as  early  as  1856,  but  has  for  its  extremely  fine 
qualities  been  retained  to  the  present  day.  Based  upon  the 
presence  of  citrate  of  silver  in  the  sensitizer,  any  variety  of 
warmer  tones,  almost  to  a  positive  red,  can  be  obtained  with  it, 
and  is  therefore  especially  commendable  to  the  use  of  the  artist. 
Take 

Pure  citric  acid 100  grains. 

Chloride  of  ammonium 100        ' ' 

Gelatine,  previously  swelled  in  cold  water 10        " 

Water 10  ounces. 

The  gelatine  is  used  to  retain  the  layer  of  sensitive  salt  at  the 
surface  of  the  paper,  but  it  does  not  affect  the  tint. 

Dissolve  the  citric  acid  in  a  small  portion  of  water,  and  neu- 
tralize with  carbonate  of  soda ;  the  quantity  (of  common  washing 
soda)  required  for  100  grains  of  citric  acid  is  228  grains  ;  add 
the  alkali  cautiously,  with  continual  stirring,  until  the  last  por- 
tions produce  no  further  effervescence,  and  the  immersed  litmus 
paper,  previously  reddened  by  the  acid,  begins  to  change  to  blue. 

The  best  paper  for  this  method  is  the  "Papier  Saxe,"  one  side 
of  which  is  to  be  floated  for  two  minutes  upon  this  salting  bath. 
Owing  to  the  gelatine  it  is  preferable  to  heat  it  slightly. 

Render  sensitive  upon  a  neutral  solution  of  nitrate  of  silver, 
50  grains  to  the  ounce  of  water,  allowing  three  minutes  contact. 
The  sensibility  to  light  is  somewhat  less  than  that  of  albumenized, 


but  greater  than  plain  paper  sensitized  with  ammonio-nitrate  of 
silver. 

When  the  proof  is  removed  from  the  printing  frame  it  is  of  a 
brown  or  purple  tint,  which  becomes  bright  red  when  immersed 
into  a  plain  solution  of  hyposulphite  of  soda.  Red  prints  of  this 
sort  are  very  popular  for  certain  engraving  or  photo-engraving 
purposes,  but  to  make  them  adaptable  for  subsequent  operations, 
they  must  be  kept  from  the  influence  of  the  gold  bath. 

Toning  and  fixing  in  one  operation,  may  be  done  with  the  pre- 
viously described  gold  and  hypo  bath,  but  the  prints  should  be 
first  washed  in  water,  to  which  a  trace  of  common  salt  has  been 
added,  in  order  to  remove  all  free  nitrate  of  silver  from  them. 
Aqua  ammonia,  if  substituted  for  the  salt  in  the  washing,  pre- 
vents changing  of  tones  when  being  dried.  Any  variety  of  tones, 
from  rich  violet  purple  to  positive  black,  are  easily  obtained,  and 
the  pictures  are  especially  distinguished  by  their  brilliant  whites. 

The  Chautauqua  Toning  Bath  may  also  be  employed  for  toning 
these  plain  prints.  Gold  acts  upon  them  with  great  rapidity  and 
it  is  therefore  advisable  to  use  the  normal  bath,  in  a  diluted  state. 
As  weak  gold  gives  invariably  the  best  results,  the  dilution  might 
be  with  plain  paper  in  the  proportion  of  1  :  3 . 

Fixing  plain  paper,  when  toned  in  the  alkaline  bath,  requires 
no  further  admonition  ;  no  other  precautions  than  those  with 
albumenized  paper  being  required.  Washing  and  hypo  elimina- 
tion are  also  the  same  ;  but  it  will  be  observed  that  hyposulphite 
of  soda  is  much  easier  and  sooner  removed  from  plain  paper 
prints  than  from  albumenized  paper. 


CHAUTAUQUA  UNIVERSITY. 

LEWIS  MILLER,  PRESIDENT. 
J.  H.  VINCENT.  CHANCELLOR.  R.  S.  HOLMES,  REGISTRAR. 


THE 


dfjautaiiqiia  pchool  of  Photograph}}, 

SCHOOL    HEADQUARTERS, 

423  BROOME  STREET,  NEW  YORK. 


CHARLES     WAGER     HULL, 
Supf.  of  Instruction,  C.  S  of  P. 


LESSON  XI. 

Cyanotypes  or  "  Blue  "  Prints. 

WE  have  learned  how  to  make  photographic  prints  upon  sil- 
vered paper,  and  we  have  received  with  those  methods,  tones  of 
various  colors,  from  a  warm  brown  to  a  positive  black.  There  is 
another  kind  of  prints  made,  not  with  the  aid  of  the  salts  of  sil- 
ver, but  with  that  of  a  certain  iron-combination,  known  by  the 
name  of  red  prussiate  of  potash,  whose  tones  are  of  a  beautiful 
and  intense  blue.  They  have  gained  immense  popularity  on  ac- 
count of  the  ease  and  the  simplicity  of  the  making. 

The  labor  required  to  make  silver  photographs,  even  when 
printed  upon  ready-sensitized  paper,  consists  of  seven  distinct 
operations  before  a  print  is  ready  to  be  mounted.  ''  Blue  "  or  Cy- 
anotype  paper  requires  but  one  ;  a  simple  washing  in  water. 

The  color  of  these  prints,  if  properly  made,  is  not  unpleasant 
but,  on  the  contrary,  is  quite  attractive,  and  collections  of  photo- 
graphs interspersed  with  them  offer  a  very  attractive  variation. 

Like  the  ready-sensitized  chloride  of  silver  paper,  the  cyano- 
iype  paper  has  become  an  article  of  trade,  and  is  manufactured 
and  sold  in  enormous  quantities,  cut  up  into  sizes  to  correspond 
with  the  negative  plates  made  with  the  cameras  of  the  American 
Optical  Company. 

All  that  is  necessary  to  procure  a  blue  print  is,  to  bring  the 
prepared  side  of  the  paper  into  absolute  contact  with  the  negative, 
expose  to  light,  and  wash. 

Besides  being  able  to  make  a  blue  print,  the  student  should 
learn  how  to  prepare  the  paper,  and  become  acquainted  with  the 
conditions  required  to  produce  a  sensitive  and  durable  article. 
In  the  first  place,  a  paper  of  any  fine  texture,  free  from  any  chem- 
ical bleaching  agents  or  their  antidotes  is  wanted.  There  is  none 
so  well  adapted  for  this  purpose  as  the  "  papier  Saxe  "  or  the 
''  Rives."  Its  sizing  is  quite  important,  and  although  the  ordin- 
ary commercial  papei  answers  quite  well,  it  is  advisable  to  give  it 


a  stronger  body,  by  immersing  it  in  albumen  beaten  to  a  froth, 
and  allowed  to  settle  again  for  the  separation  of  the  clear  liquid. 
Four  parts  of  water  mixed  with  one  part  of  the  clarified  albumen 
is  a  good  proportion.  After  leaving  the  paper  in  this  mixture  for 
a  minute,  it  may  be  hung  up  to  dry  spontaneously,  and  the  al- 
bumen be  coagulated  by  placing  the  paper  in  a  steam  chest  or  by 
hanging  it  up  near  a  very  hot  stove. 

For  sensitizing  the  paper  we  prepare  two  solutions: 

A. — Citrate  of  iron  and  ammonia !_%  ounce. 

Water 8 

B. — Red  prussiate  of  potash ll£  ounce. 

Water  8 

Filter  and  keep  separately  in  the  dark  room.  Before  use,  equal 
volumes  of  these  are  mixed  together  and  poured  into  a  flat  dish 
or  tray.  After  all  foam  or  air  bubbles  have  disappeared,  the 
paper  is  floated  upon  this  solution  for  three  minutes,  observing 
the  same  precaution  required  in  silvering  albumen  paper.  Then 
hang  up  to  dry. 

All  this  is  done  in  the  dark  room  or  a  much  subdued  light. 
When  dry,  the  paper  is  ready  for  printing  at  once,  or  it  may  be 
preserved  for  future  use.  If  intended  to  be  kept  for  a  length  of 
time  the  pieces  of  the  required  size  are  best  brought  into  close 
contact  with  each  other,  wrapped  up  in  waxed  or  paraffin  paper 
and  subjected  to  a  slight  pressure.  This  is  done  to  prevent 
moisture  or  impure  air  from  coming  into  contact  with  the  sensi- 
tive surface,  which  would  speedily' change  the  original  greenish- 
yellow  color  to  a  muddy  greenish-blue,  denoting  a  chemical  de- 
composition. Paper  having  undergone  such  a  change  is  not  easy 
to  print  upon.  It  prints  slow,  for  it  has  lost  much  of  its  sensi- 
tiveness, the  shadow  parts  of  the  negative  do  not  print  out  in 
detail,  and  to  obtain  pure  whites  is  impossible. 

The  mode  of  printing  being  the  same  as  that  upon  other  sen- 
sitive substances,  requires  necessarily  absolute  contact.  Printing 
in  sunlight  is  admissible,  and  the  operation  is  done  quicker  than 
upon  silver  paper,  and  should  be  carried  far  enough  to  give  the 
darkest  parts,  that  is  those  under  the  clearest  parts  of  the  nega- 
tive, a  decided  reddish  bronze  color.  When  completed,  the  print 
is  removed  from  the  press  and  washed  in  pure  water,  till  the  pic- 
ture is  perfectly  well  developed,  and  stands  out  with  a  beautiful 
blue  tone  upon  a  white  ground. 

When  the  water  dripping  from  it  ceases  to  be  of  a  yellow  tinge, 
the  operation  is  completed,  and  the  result  is  a  permanent  and 
3 


durable  picture  which  is  not  effected  by  light  and  but  little  by  at- 
mospheric influences. 

A  few  drops  of  hydrochloric  acid  intensifies  the  blue  color, 
and  a  little  sulphuric  acid  gives  it  a  greenish  tint.  Ammonia 
gives  it  a  purple  color,  and  renders  the  picture  lighter  and  can 
be  used  therefore  to  reduce  a  print  if  too  dark. 

Blue  paper  is  extensively  used  for  the  reproducing  of  tracings 
and  drawings.  The  copies  are  naturally  negatives,  that  is  the 
black  lines  of  the  original  appear  white  upon  a  blue  ground.  Al- 
though the  general  effect  of  the  picture  is  thus  reversed,  blue 
printing  has  found  just  in  this  particular  line  the  most  extensive 
employment. 

The  tourist  anxious  to  see  a  proof  of  the  negative  made,  can 
judge  of  its  general  qualities  when  printed  upon  cyanotype  paper 
without  resorting  to  the  troublesome  silver  printing  and  gold 
toning,  and  many  amateurs  are  so  partially  inclined  to  blue  prints 
that  they  admit  them  to  their  albums. 

Efforts  have  been  made  to  convert  blue  prints  into  prints  of 
other  colors,  especially  those  of  dark  brown  or  black  shades,  but 
they  have,  according  to  all  reliable  authorities,  signally  failed.  An 
old  method  for  changing  color  is  to  bleach  the  blue  by  means  of 
a  carbonated  alkali,  leaving  upon  the  paper  a  deposit  of  sesqui 
oxide  of  iron,  which  is  afterwards  developed  with  tannic  or  gallic 
acid.  Clear  whites  are  almost  impossible  to  obtain,  and  the  gen- 
eral tone  of  the  transferred  print  may  be  acceptable  by  some,  but 
certainly  is  not  to  the  general  public. 

Red  prussiate  of  potash  in  substance  or  in  solution  is  sensitive 
to  light  and  should  therefore  be  kept  in  the  dark. 

The  citrate  of  iron  and  ammonia  is  very  hygroscopic,  and 
when  exposed  to  air  attracts  so  much  moisture  that  it  will  be  de- 
composed and  reduced  to  a  black  pulpy  mass.  We  must  there- 
fore keep  it  in  well-stoppered  bottles. 


CHAUTAUQUA  UNIVERSITY. 

LEWIS  MILLER,  PRESIDENT. 
J.  H.  VINCENT,  CHANCELLOR.  R.  S.  HOLMES,  REGISTRAF 


THE 


f>cljool  of  photograph^ 


SCHOOL    HEADQUARTERS. 

423  Broome  Street,  New  York. 

CHARLES     WAGER     HULL, 
Supt.  of  Instruction,  C.  S.  of  P, 


LESSON  XII. 

Printing  on  Permanent  Bromide  of  Silver 
Paper. 

THIS  paper,  entirely  different  in  its  preparation  from  those  we 
have  already  become  acquainted  with,  is  extremely  sensitive  to 
light,  and  requires,  therefore,  but  short  exposures.  The  mode  of 
operating  is  not  the  same  or  similar  to  any  of  those  sensitive 
papers  we  have  considered  before,  and  requires  an  essentially 
different  treatment.  The  picture  is  not  secured  by  a  complete 
printing-out,  but  by  development  conducted  as  in  the  negative 
processes,  and  with  chemicals  not  described  in  previous  instruc- 
tions. 

The  uses  of  the  bromide  paper  are  almost  unlimited  in  their 
variety. 

For  making  contact  prints  from  negatives  of  all  kinds,  por- 
traits, views,  interiors,  architectural  and  mechanical  subjects,  it  is 
unsurpassed,  either  for  quickness  of  execution  or  artistic  effect. 
The  pure,  soft  black  and  gray  tones,  and  steel  engraving  effects 
obtained,  and  the  absence  of  the  conventional  glossy  surface, 
usual  in  photographs,  are  points  in  its  favor  that  are  appreciated 
by  artists  and  connoisseurs  of  refined  taste. 

For  copying  patent  office  drawings,  engineers'  and  architects' 
plans,  it  surpasses  all  other  processes  in  quickness  and  quality  of 
result.  It  is  used  by  botanists  for  making  copies  of  leaves,  etc., 
by  contact  printing. 

It  is  invaluable  for  use  in  meteorological  and  astronomical  re- 
cording instruments.  In  making  quick  proofs  from  wet  nega- 
tives, it  enables  the  photographer  to  see  his  result  without  wait- 
ing for  his  negative  to  dry. 

But  perhaps  the  most  important  application  of  permanent  bro- 
mide paper  is  to  the  process  of  enlarging,  /.  «?.,  the  making  of 
large  positives  from  small  negatives. 
2 


Owing  to  its  great  sensitiveness,  it  will  receive  and  retain  an 
image  projected  upon  it  by  means  of  an  apparatus  similar  in 
principle  to  a  magic  lantern,  thus  enabling  the  photographer  to 
make  prints  of  any  size  from  small  negatives.  Such  prints  pre- 
sent the  effect  of  fine  crayon  drawings,  at  the  same  time  retain- 
ing the  photographic  fidelity  of  likeness  and  detail. 

The  exposure  required  for  this  extremely  sensitive  paper  varies 
with  the  intensity  of  the  negative  and  the  quality  and  intensity 
of  the  light,  but  may  be  approximately  stated  to  be,  using  as  thin 
negatives  as  will  make  good  prints,  one-quarter  second  by  dif- 
fused daylight,  or  ten  seconds  at  a  distance  of  one  foot  from  a 
No.  2  kerosene  burner.  Very  thin  negatives  should  be  printed 
by  weak  yellow  light,  like  that  obtained  from  a  kerosene  lamp 
turned  down  a  little  below  the  normal  intensity.  In  this  way  a 
strong,  vigorous  print  may  be  obtained  from  a  negative  that 
would  otherwise  be  too  thin  and  flat.  Strong,  intense  negatives 
are  best  printed  by  daylight. 

Permanent  bromide  paper  is  manufactured  in  various  grades 
of  sensitiveness  and  surface.  For  contact  printing  of  proofs,  for 
drawings,  tracings,  or  those  from  ordinary  negatives,  the  "A,"  with 
smooth  surface,  is  best  adapted;  while  for  enlargements,  especially 
when  to  be  finished  by  the  artist's  hand,  the  "C,"  of  rougher 
grain,  is  preferred.  All  of  the  different  grades  are  sold  cut  in 
popular  sizes  and  put  up  in  light-tight  packages,  or  in  endless 
roles,  well  protected  against  the  action  of  undue  light.  For  con- 
tact printing  the  paper  is  laid  in  the  printing  frame  upon  the 
negative  as  heretofore  described,  and  for  enlargements  is  fas- 
tened against  the  easel,  to  be  explained  later  on.  Owing  to  its 
gelatinized  surface,  the  edges  of  the  paper  curl  up  on  the  coated 
side,  and  to  make  the  developer  take  freely  to  it,  immersion  in 
water  becomes  necessary  before  development.  When  perfectly 
flattened  out,  the  water  may  be  poured  off  and  the  developer 
applied. 

FORMULA  FOR  DEVELOPER. 

1. — Oxalate  of  potash 1  pound. 

Hot  water. 3  pints. 

Acidify  with  sulphuric  or  citric  acid.     Test  with  litmus  paper. 

2. — Protosulphate  of  iron 1    pound. 

Hot  water 1    quart. 

Sulphuric  acid  (or  citric  acid,  i  ounce) -J  dram. 

3. — Bromide  potassium 1  dram. 

Water 1  quart. 

3 


These  solutions  keep  separately,  but  must  be  mixed  only  for 
immediate  use. 

Take  in  a  suitable  tray  :  No.  1,  six  ounces  ;  No.  2,  one  ounce  ; 
mix  in  the  order  given  ;  use  cold. 

The  image  should  appear  slowly,  and  should  develop  up  strong, 
clear  and  brilliant.  When  the  shadows  are  sufficiently  black, 
stop,  pour  off  the  developer  and  flood  the  print  with  the  clearing 
solution,  consisting  of  one-quarter  of  an  ounce  of  citric  acid  to 
one  quart  of  water.  Repeat  washing  with  the  acid  water  three 
or  four  times,  rinse  well  with  pure  water,  and  finally  fix  in  hypo- 
sulphite of  soda,  three  ounces  of  which  is  dissolved  in  one  pint  of 
water.  When  perfectly  fixed,  which  takes  about  ten  minutes, 
wash  again,  submit  to  the  alum  bath  and  final  washing,  which  is 
greatly  accelerated  by  the  use  of  Flandreau's  hypo  eliminator,  as 
in  the  case  of  other  kinds  of  prints. 

REMARKS  ON  DEVELOPMENT. 

The  developer  in  use  is  termed  by  photographers  the  "  ferrous 
oxalate  "  developer,  and  consists  in  reality  of  the  ferrous  oxalate 
dissolved  in  an  excess  of  oxalate  of  potash.  The  mixture  should 
present  a  clear,  dark-ruby  color.  If  turbid,  too  much  of  the  iron 
solution  has  been  added,  and  the  iron  oxalate  formed  is  in  excess 
of  the  power  of  the  oxalate  of  potash  present  to  keep  it  in  solu- 
tion, hence  a  part  of  the  iron  salt  remains  undissolved,  and  pre- 
cipitates in  the  form  of  a  bright  yellow  powder.  Such  developer 
is  unfit  for  use. 

Care  should  be  taken  to  employ  oxalate  of  potash  only  when  in 
a  perfectly  neutral  state,  or  when  acidity  is  slightly  prevailing. 
An  oxalate,  reacting  alkaline,  tends  to  make  hard  and  chalky 
prints  without  half  tones,  effects  erroneously  ascribed  at  times  to 
under-exposures.  The  only  difficulty  occurring  with  bromide 
prints,  is  a  misjudged  time  of  exposure.  Over  and  under-expos- 
ures can  be  observed  with  the  ferrous  oxalate  developer  in  the 
same  way  as  the  effects  shown  in  the  negative  process  with  pyro- 
gallic  acid.  Under-exposures  give  hard,  black  and  white  prjnts 
without  any  half  tones  or  fine  gradations. 

For  over-exposures  we  have  remedies  on  hand  by  which  we  can 
counteract  their  effects.  One  of  these  is  Bromide  of  Potassium 
Solution  No.  3,  which,  when  judiciously  used,  will  restrain  the 
forcible  action  of  the  developer,  and  modify  the  gray  tone  result- 
ing without  it. 

4 


Too  much  of  it,  however,  tends  to  make  a  yellowish  or  olive 
green  tone  which  is  by  no  means  agreeable.  With  a  careless  ap- 
plication of  bromide  of  potassium  there  is  danger  of  spoiling  the 
print  entirely. 

A  better  restrainer  is  undoubtedly  a  developer  prepared  some 
time  previous  to  its  use,  and  when  it  has  attained  partly  to  a 
higher  state  of  oxidation.  Whenever  an  over-exposure  may  be 
suspected,  it  is  advisable  to  commence  development  with  this 
partly  oxidized  solution  and  when  the  general  outlines  and 
deeper  shadows  of  the  picture  are  fairly  out,  substitute  for  it  a 
freshly-made  preparation,  and  counterbalance  its  action,  if  too 
forcible,  again  with  the  old.  The  operation  probably  requires 
a  little  more  nicety  than  the  ordinary  method,  but  the  resulting 
tones  are  decidedly  better  and  richer  than  those  resulting  from 
an  excessive  use  of  bromide  of  potassium. 

The  office  of  the  acid  clearing  solution  is  to  dissolve  the  iron 
salt  that  has  entered  into  the  pores  of  the  paper  supporting  the 
gelatine  film  during  the  development.  Without  it  the  prints 
would  be  of  a  yellowish,  muddy  color,  wanting  in  the  brilliancy 
and  clearness  for  which  bromide  prints  are  noted. 

Permanent  bromide  prints  should  not  be  dried  between  blotters 
like  albumenized  paper,  but  should  be  hung  over  a  line,  or  laid 
back  down  upon  glass  or  clean  paper. 

ENAMELING. 

Squeegee  the  wet  print,  face  down,  on  a  polished  piece  of  hard 
rubber  or  ebonite  ;  when  dry  the  print  will  peel  off  with  a  fine 
polished  surface.  The  print  should  be  slipped  on  to  the  rubber 
plate  under  water  to  avoid  air  bells. 

FLEXIBLE  PRINTS. 

Permanent  bromide  prints  soaked  in  a  mixture  of  glycerine, 
five  ounces,  and  water,  twenty-five  ounces,  and  dried,  will  not 
curl,  and  may  be  used  for  book  illustrations  unmounted.  The 
heavier  papers  "B"  and  "C,"  are  especially  adapted  for  this 
purpose. 

STRAIGHTENING  UNMOUNTED  PRINTS. 

After  drying,  prints  may  be  straightened  by  the  scraping  action 
of  a  sharp-edged  ruler  applied  to  the  back  ;  the  corner  behind 
the  ruler  being  lifted  as  the  ruler  is  passed  along. 

6 


ENLARGING  APPARATUS. 

The  operation  of  enlarging  on  permanent  bromide  paper  in- 
volves the  same  principles  as  those  underlying  the  making  of  a 
negative  ;  it  is  simply  photographing  on  a  large  scale  the  neg- 
ative instead  of  the  original.  To  avoid  the  necessity  of  using  a 
large  camera,  the  dark-room  itself  is  made  to  take  the  place  of 
the  camera  body,  and  the  negative  is  placed  in  an  opening  in  the 
dark-room  shutter  so  that  all  the  light  will  come  through  it  to  the 
lens.  See  Fig  1. 


FIG.  1. 


The  above  cut  represents  an  enlarging  apparatus  that  any  pho- 
tographer can  improvise  from  ordinary  apparatus  and  material, 
with  the  expenditure  of  a  few  hours'  time.  To  construct  it  pro- 
ceed as  follows  : 

Cut  a  hole  in  the  dark-room  shutter  two  sizes  larger  than  the 
largest  negative  to  be  enlarged  from,  fit  into  the  opening  a  frame 
about  two  or  three  inches  deep,  glazed  on  the  outside  with  a  sheet 
of  ground  glass.  On  the  inside  edges  of  the  frame,  top  and  bottom, 
arrange  grooves  in  which  to  slide  the  negative  ;  when  the  nega- 
tive is  in  position  it  will  be  brilliantly  illuminated  against  the 
ground  glass.  Now,  on  a  table  or  shelf,  adjusted  in  front  of  the 
negative  box,  place  an  ordinary  camera  having  the  ground  glass 
removed,  point  the  lens  toward  the  negative,  and  connect  the 
lens  and  negative  box  by  means  of  a  bag  of  opaque  cloth,  open 
at  both  ends  and  provided  with  elastic  bands  to  close  it  tight 
around  the  lens  and  negative  box.  This  will  prevent  any  light 


coming  into  the  dark  room,  except  through  the  lens.  See  Figs. 
1  and  2. 

In  this  apparatus  the  camera  body  serves  no  useful  purpose  ; 
all  that  is  required  is  to  support  the  lens.  In  case  a  portrait  lens 
is  used  it  should  be  put  in  position  so  that  the  back  lens  will  be 
next  the  negative  instead  of  as  shown  in  the  cut. 

The  easel  to  hold  the  sensitive  paper  is  the  next  requisite,  and 
this  may  be  constructed  by  fastening  a  large,  flat  board  in  an  up- 
right position,  upon  a  box  of  suitable  size  to  serve  as  a  base,  so 
that  the  whole  may  be  moved  to  and  fro  to  regulate  the  size  of 
the  enlargement.  The  face  of  the  easel  should  be  covered  with 
white  paper.  Now,  if  the  easel  is  put  in  position,  facing  the 
camera,  the  image  can  be  focused  on  the  screen  by  sliding  the 
camera  backward  or  forward  on  the  shelf. 


FIG.  2. 

The  size  of  the  enlargement  will  depend  upon  the  length  of 
focus  of  the  lens,  and  the  distance  the  easel  is  set  from  the 
negative. 

Any  lens  that  will  make  a  negative  can  be  used  for  enlarging, 
and  the  proper  size  for  the  lens  depends  wholly  upon  the  negative 
to  be  enlarged  from,  and  not  at  all  upon  the  enlargement  to  be 
made.  If  the  lens  will  cover  the  negative,  it  will  make  an  en- 
largement from  it  of  any  size. 

For  enlarging  from  negatives  5x8  inches  and  under,  a  half  size 
portrait  lens  is  suitable.  It  can  be  worked  nearly  wide  open  to 
heads,  but  will  have  to  be  stopped  down  for  half  and  full  length 
figures.  Rapid  rectilinear  lenses  are  also  suitable,  but,  of  course, 
do  not  work  quite  as  quick  on  heads  as  portrait  lenses,  because 
they  have  not  as  large  aperture.  For  full  and  half  length  figures 
and  views  they  are  quite  as  rapid,  because,  for  this  purpose,  the 
portrait  lens  requires  to  be  stopped  down  as  far  as  the  rapid 
rectilinear. 

7 


HINTS. 

Mealy  Mottled  Prints — Over-exposure  and  short  development 

Greenish  Tones  are  obtained  by  over-exposure  and  too  much 
bromide. 

Forcing  Development  does  not  give  good  results  for  the  above 
reason. 

Face  of  Permanent  Bromide  Paper  can  always  be  distinguished 
by  its  curling  in.  Convex  side  is  always  the  back. 

Fixing — The  operator  can  tell  when  a  bromide  print  is  fixed 
by  looking  through  it  or  upon  it  in  a  good  light,  unfixed  portions 
will  be  greenish  yellow. 

Yellou>  Prints — Prolonged  development  will  cause  yellow  prints 
by  depositing  iron  in  the  paper.  The  exposure  must  be  correct, 
so  as  to  allow  of  quick  development. 

Running  Water  is  not  so  sure  a  means  for  washing  prints  as 
changing  them  from  one  tray  to  another,  allowing  them  to  soak 
at  least  ten  minutes  in  each  fresh  water  ;  twelve  changes  are 
sufficient ;  no  less. 

THE  PERMANENCY  OF  PERMANENT  BROMIDE  PRINTS. 

It  should  be  understood  that  a  print  on  permanent  bromide 
paper  is  a  very  different  thing  from  an  ordinary  photograph  on 
albumen  paper.  In  the  first  case,  the  image  is  produced  by 
development  upon  a  substance  containing  no  free  nitrate  of  silver. 
In  the  second  case,  the  image  is  formed  by  light  alone  acting 
upon  an  organic  compound  of  silver  in  the  presence  of  free 
nitrate  of  silver ;  in  this  case  the  image  is  known  to  be  un- 
reliable as  to  permanence,  while  in  the  case  of  the  permanent 
bromide,  all  the  evidence  points  to  as  great  permanence  as  can 
be  desired. 

Do  not  suppose  that  a  permanent  bromide  print  is  liable  to 
fade  because  the  paper  turns  yellow.  All  paper  will  become  yel- 
low after  exposure  to  light  and  air.  For  example,  see  any  old 
engraving  or  etching.  This  yellowing  or  mellowing  of  .the  paper 
has  nothing  whatever  to  do  with  fading. 


CHAUTAUQUA    UNIVERSITY. 

LEWIS  MILLER,  PRESIDENT. 
J.  H.  VINCENT,  CHANCELLOR.  R.  S.  HOLMES,  REGISTRAR. 


He  Gfyautaip  sstool  of  PiotognM. 

SCHOOL    HEADQUARTERS, 
4=23  Broome  Street,  New  York. 


CHARLES    WA.GER 

Supt.  of  Instruction,  C,  S.  of  P. 


LESSON  No.  XIII. 

Artistic    Printing. 

IT  is  but  a  little  while  ago  when  the  primitive  amateur  pho- 
tographer thought  his  duty  done  by  exposing  his  ready-made 
dry  plates  and  leaving  to  a  "  professional"  the  labor  of  developing 
and  printing.  He  has  since  discovered  that  his  own  developing 
and  printing  are  as  essential,  and  even  more  so,  than  the  mere 
exposure,  in  order  to  reproduce  the  picture  which  he  had  in  his 
mind's  eye. 

On  the  proper  development  of  correctly  and  faulty  exposures, 
former  lessons  have  given  instructions.  The  following  remarks 
are  intended  for  those  who  having  mastered  plain  printing  desire 
to  have  some  knowledge  of  more  artistic  methods,  viz.  :  I.  Of 
Printing  in  Medallion  Style  ;  II.  Vignetting ;  III.  Flushing  or 
Tinting  the  White  Background ;  IV.  Combining  I.  and  II.  ; 
V.  Printing-in  Backgrounds  ;  VI.  Printing  in  Clouds. 

I.  In  order  to  print  portraits  in  medallion  style  it  will  be  neces- 
sary to  procure  some  metal  oval  and  circle  guides  and  a  revolving 
Robinson  print  trimmer.  It  will  be  desirable  to  have  at  least  two 
sizes  of  the  guides  for  the  carte  de  visite  and  two  sizes  for  the 
cabinet  form.  Cut  a  suitable  mask  on  orange  post-office  paper 
and  paste  it  on  the  face  of  the  negative.  This  will  give  you  in 
printing  an  oval  or  circle  with  a  white  border.  In  order  to 
tint  the  border,  paste  the  cut-out  oval  on  a  clean  glass  of  suitable 
size.  Place  your  print  on  another  glass,  adjust  the  "  cut-out" 
face  down  over  it  and  expose  to  light,  more  or  less  according  to 
taste.  The  tinted  border  may  be  ornamented  in  various  ways, 
1 


by  a  piece  of  tulle  or  lace  stretched  over  it,  etc.     But  the  plain 
tinted  border  will  be  the  most  satisfying. 

II.  For  vignetting  portraits,  it  is  desirable  that  the  original 
should  have  been  taken  against  a  light  (not  white)  background  ; 
if  the  background  be  too  dark,  it  must  be  lightened  artificially,  as 
/.  t.,  by  covering  the  glass  side  of  the  negative  with  ground  glass 
varnish  and  darkening  it  with  a  stump  and  black  lead,  begin- 
ning close  to  the  head.  Next,  cut  out  a  mask  close  to  the  figure  ; 
for  a  portrait  the  pear  shape  will  be  found  most  suitable.  Cut 
the  mask  not  in. straight  but  in  irregular  wavy  lines,  similar  to 
the  cut  of  Weymouth's  vignetter.  Cover  your  printing  frame 


with  a  stout  card-board,  into  which  a  square  or  an  oval  opening 
is  cut  out,  large  enough  to  receive  any  size  of  masks.  This  open- 
ing is  to  be  covered  with  a  piece  of  tissue  paper  of  even  texture. 
Underneath  this,  paste  your  mask  and  back  the  whole  on  the 
printing  frame,  the  tissue  paper  uppermost,  next  to  the  light. 
Adjust  the  negative  in  proper  position,  looking  through  against 
the  light ;  if  a  greater  number  of  prints  of  the  same  negative  is 
desired,  paste  the  negative  in  proper  position  by  means  of  some 
strips  of  glued  paper.  If,  after  printing  a  proof,  the  gradations 


of  the  vignette  should  prove  too  abrupt,  it  may  be  remedied  by 
(1),  widening  the  space  between  the  negative  and  the  mask;  (2) 
by  painting  on  the  glass  side  of  the  negative  with  Russian  or 
indigo  blue  a  contour  in  waving  outlines  according  to  taste  ; 
(3)  by  encircling  the  head  with  loose  cotton  wool,  always  on  the 
glass  side  of  the  negative. 

III.  Flushing  or  tinting  the  white  background  of  a  vignette  will 
be  of  advantage  in  prints  from  flat  negatives.     The  dull  lights 
in  the  print  will  be  enhanced   by  subduing  the   extreme  white 
of  the  background.     The  easiest  and  safest  way  to  do  this  is  to 
cut  out  a  mask  slightly  smaller  than  the  head  and  figure  (omitting 
the  shadows  caused  by  the  vignette  printing).     Place  the  print 
into  a  printing  frame,  and  over  the  glass  outside  you  mask  and 
expose  to  light,  moving  with  a  darning-needle    (which   hardly 
throws  any  shadow),  waxed  at  one  end  in  order  to  get  a  tack  on 
your  cut-out  mask,  moving  it  slightly  during  exposure. 

IV.  A  combination  of  the  vignette,  plain  or  tinted,  can  then 
be  made  with  the  medallion  style,  for  which  no  further  instruc- 
tions need  be  given. 

Taste  and  the  quality  of  the  negative  must  guide  the  printer 
which  of  the  described  ways  of  printing  will  show  the  subject  to 
best  advantages.  A  child's  or  a  very  young  lady's  head  will  show 
best  closely  vignetted  on  a  white  background,  while  a  gray  head 
with  whiskers  will  be  most  effective  on  a  plain  dark  background. 

V.  Printing-in  backgrounds  either  natural  or  artificial,  for  por- 
traits or  groups  is  a  more  difficult  subject,  and  will  require  some 
experimenting  before  attaining  success.     The  mode  of  operation 
will  consist  (1)  in  obliterating  any  backgrounds  of  your  figures 
by  the  use  of  any  opaque  color  close  to  the  figure  or  figures,  and 
to  print  them  in  proper  position  ;    (2)  in  choosing  a  background 
which  is  lighted  from  the  same  side  as  the  figures  ;  (3)  in  cutting 
out  masks  of  the  figures  slightly  smaller  than  the  originals.     Now 
place  your  foreground  negative  into  the  printing  frame  and  your 
figures  over  it  and  close.     Cover  outside  of  the  glass  of  the  print- 
ing frame  the  figures  with  your  cut-out  mask  and  expose  to  light, 
moving  the  mask  as  before  directed.     The  degree  of  intensity  of 
the  background  must  be  examined  from  time  to  time  in  order  to 
get  perfect  harmony  between  the  quality  of  tone  between  figures 
and  background- 

VI.  Printing-in  clouds  into  landscape  photographs.     A   land- 
scape photograph,  be  it  ever  so  successful,  with  a  clear  blue  (in 


photography,  a  white)  sky,  is  but  a  half-finished  picture.  To  give 
animation  to  the  blank  space,  especially  when  the  horizon  is  low, 
it  will  be  necessary  to  enliven  it  with  cloud-life. 

Secure  on  a  favorable  day  cloud  negatives  from  some  elevated 
point,  tilting  the  camera  upwards  in  order  to  get  the  greatest 
amount  of  sky  on  your  plate.  Avoid  over-developing,  as  it  is 
desirable  to  have  quick-printing  negatives.  Mark  them  according 
to  the  exposure,  scratching  in  some  corner  :  S  M.,  south  morn- 
ing ;  E  E.,  east  evening,  etc.  Do  not  hesitate  to  point  your  lens 
direct  against  the  sun,  especially  on  fine  sunset  evenings  ;  the 
transparent  spot  of  the  sun  disc  is  easily  blocked  out  by  a  circular 
cut-out  opaque  paper,  somewhat  larger  than  the  sun  disc,  gummed 
on  the  glass  side  of  the  negative. 

Having  thus  obtained  a  number  of  cloud  negatives  suitable  in 
lighting  for  any  of  your  landscapes,  the  difficult  part  remains  of 
printing  them  into  your  picture  without  showing  a  dividing  line. 
Proceed  as  follows  :  Make  a  mask  of  your  landscape  on  some 
opaque  paper  (post-office  paper  will  do),  tracing  the  outlines  of 
the  horizon  in  a  rough  way,  not  minding  single  tree-tops  rising 
above  it.  Place  your  print  over  the  selected  cloud  negative  in 
a  printing  frame,  and  your  mask  outside  of  the  frame  in  position. 
Expose  to  the  sun,  constantly  moving  your  mask  up  and  down, 
also  sideways ;  never  hold  your  mask  too  high  above  the  horizon 
point,  but  rather  move  it  an  eighth  of  an  inch  or  so  below.  As  it 
is  easy  to  observe  from  time  to  time  the  effect  of  your  printing, 
you  can  manage  the  mask,  raising  it  higher,  lower,  or  cornerwise, 
according  to  requirement.  The  result  will  be,  after  a  little  prac- 
tice, a  perfect  blending  of  the  two  negatives. 

It  will  be  advisable  to  secure  cloud  negatives  on  larger  plates 
than  those  used  for  the  landscape.  By  placing  the  print  in  differ- 
ent positions,  a  variety  of  cloud  effects  can  be  obtained  from  the 
same  cloud  negative. 

In  conclusion,  let  us  warn  the  young  photographers  never  to 
print  the  full  size  of  their  negatives  when  they  use  lenses  of 
very  short  focus,  as^.  /.,  the  wide-angle  lenses,  for  the  reason  that 
only  about  two-thirds  of  the  center  is  in  true  perspective  and  the 
borders  outrageously  exaggerated.  Even  with  negatives  made 
with  long  focus  lenses  it  will  be  advisable  to  make  some  sacrifice 
for  the  benefit  of  a  more  artistic  result.  The  printing  of  land- 
scapes in  medallion  and  vignetted  form  gives  a  most  charming 
effect,  and  many  a  faulty  negative  may  give  excellent  results  by 
this  mode  of  treatment. 


CHAUTAUQUA  UNIVERSITY, 

LEWIS  MILLER.  PRESIDENT. 
H.  VINCENT,  CHANCELLOR.  R.  S.  HOLMES,  REGISTRAR. 


THE 


(Sjanfouqua  ^cjool  of  Photographi}, 

SCHOOL    HEADQUARTERS, 

423  BROOME  STREET,  NEW  YORK. 


CHARLES    WAGER     HULL 
Supt.  of  Instruction,  C.  S.  of  P. 


LESSON    XIV. 

Trimming  and  Mounting  the  Prints. 

Trimming. — Albumen  prints,  having  been  thoroughly  washed 
and  the  last  traces  of  hypo  having  been  eliminated  from  them, 
may  be  dried  and  trimmed  or  cut  to  appropriate  sizes  and 
shapes  preparatory  to  mounting.  For  economical  reasons,  many 
photographers  trim  their  pictures  before  toning  and  fixing,  and 
collect  the  paper  clippings  containing  small  amounts  of  silver, 
to  recover  by  chemical  processes  the  precious  metal. 

Prints  should  be  dried  spontaneously  and  not  by  heat.  They 
are  hung  up  two  by  two  and  back  to  back  with  clips  and  strung 
on  a  line. 


LOCKWOOD'S  CLIP. 

The  trimming  of  the  photograph  should  always  be  neatly  and 
carefully  done.  The  edges  should  be  untorn  and  the  form  or 
shape  should  be  true.  A  knife  is  often  used  with  a  glass  or  metal 
form,  but  the  invention  of  Mr.  S.  M.  Robinson,  known  as  the 
Robinson  Trimmer,  has  almost  displaced  the  knife.  These  trim- 
mers are  made  in  two  forms,  the  one  illustrated  by  Fig.  1  being 
constructed  so  as  to  revolve  in  a  socket  in  order  to  follow  accu- 
rately an  oval  or  round-cornered  metal  '*  guide,"  and  the  other 
in  Fig.  2,  known  as  the  "  straight  cut,"  is  for  trimming  straight 
edges,  a  metal  guide  being  used  with  it  also,  or  a  glass  form. 

3 


The  theory  of  these  trimmers  is  that  instead  of  cutting  they 
pinch  off  the  surplus  paper,  thereby  giving  a  nicely  beveled  edge 
to  the  print,  and  they  are  far  superior  to  the  knife  or  scissors  if 
held  and  used  as  indicated  by  the  drawings. 

To  trim  the  print  well  it  must  be  laid  upon  a  hard  surface. 
Many  use  a  glass,  others  again  trim  upon  a  sheet  of  zinc.  With 
the  former,  the  cutting  tool  is  very  soon  dulled,  and  with  the 
other,  the  metal  is  cut  up  and  roughened  so  much  that  a  clean  cut 
soon  becomes  an  impossibility.  A  better  mode  is  to  paste  a  sheet 
of  well-sized  paper  on  the  glass,  which  when  dry  gives  sufficient 
resistance  to  the  trimmer  without  injuring  its  sharp  edge,  and 
the  surface  not  being  so  slippery  as  glass  allows  the  print  to  rest 
well  upon  it  during  the  manipulation. 


FIG.  1.  FIG.  2. 

ROBINSON'S  TRIMMERS. 

Before  mounting,  the  prints  are  wetted  again  in  clean  water, 
and  when  perfectly  pliable  laid  upon  blotting  paper  in  several 
thicknesses  face  down,  and  piled  upon  each  other  in  such  quan- 
tities as  to  allow  of  comfortable  pasting. 

Mounting. — A  very  durable  and  adhesive  mountant  is  the 
S.  P.  C.  parlor  paste. 

Another  good  paste,  easily  made  by  anybody,  is  the  following  : 

Take  good  laundry  starch If  ounces. 

Sheet  gelatine  or  white  glue 80    grains. 

Put  the  starch  into  a  small  pan,  add  one  ounce  of  water,  and 
mix  thoroughly  with  a  spoon  or  the  ordinary  mounting  brush, 
until  it  is  like  a  thick  cream,  then  add  fourteen  ounces  of  water, 
and  the  gelatine,  broken  into  small  fragments.  Boil  for  four  or 
five  minutes,  set  aside  until  partially  cold,  then  add  one  ounce  of 
alcohol  and  six  drops  of  pure  carbolic  acid.  We  have  now  fif- 
4 


teen  ounces  of  a  very  good  and  durable  paste  that  will  keep  well 
in  stoppered  bottles,  is  smooth  as  cream,  without  lumps  or  grit. 

Previous  to  applying  the  paste  all  superfluous  water  is  squeezed 
from  the  pile  of  prints  with  a  slight  pressure  between  blotting 
paper,  after  which  the  mounting  can  be  commenced.  A  flat 
bristle  brush  is  dipped  into  the  paste,  and  then  drawn  with  slight 
force  over  the  print  laying  on  top  of  the  pile.  It  is  drawn  sev- 
eral times  and  in  opposite  directions  over  the  print  without  leav- 
ing more  paste  than  necessary  for  adhesion.  The  print  is  then 
lifted  up  with  the  point  of  a  knife,  and  placed  in  proper  position 
upon  the  mount.  With  a  stout  piece  of  paper  and  an  ivory  paper 
cutter  or  similar  tool,  the  print  must  be  laid  flat,  all  air  bubbles 
expelled  from  under  it,  and  when  adhering  uniformly  to  all  parts 
of  the  mount,  laid  aside  for  drying,  with  the  face  side  down. 
Care  must  be  taken  to  apply  not  more  paste  than  is  needed  to 
fasten  the  print  to  the  mount.  Highly  glazed  mounts,  at  present 
so  much  in  vogue,  are,  on  account  of  their  greasy  enamel,  quite 
difficult  to  mount  upon.  To  make  photographs  adhere  to  them 
uniformly,  it  is  best  to  add  and  mix  well  with  the  fifteen  ounces 
of  paste  one-half  ounce  of  ammonia.  A  part  of  the  ammonia 
saponifies  the  greasy  matter,  the  rest  evaporates.  The  method  is 
very  easy  to  work  and  not  injurious  to  the  picture. 

Blue  prints  and  photographs  on  plain  paper  are  similarly 
treated,  but  do  not  require  to  be  wetted  ;  and  it  is  probably  bet- 
ter to  paste  them  when  in  a  dry  state. 

Permanent  bromide  prints  may  be  mounted  wet  or  dry  ;  the 
prints  should  not  be  dried  between  blotters  like  albumenized 
paper,  but  should  be  hung  over  a  line,  or  laid  back  down  upon 
glass  or  clean  paper.  To  mount,  brush  over  the  back  with  thin 
starch  paste,  lay  the  print  on  the  mount  and  rub  into  contact 
with  a  soft  cloth. 

For  very  large  pictures,  cover  an  artist's  stretcher  frame  with  a 
piece  of  common  white  muslin,  by  stretching  it  tightly  while  dry 
and  tacking  it  on  the  outside  edges.  Give  the  cloth  a  coat  of 
starch  paste,  rubbing  it  well  in  and  avoiding  streaks  and  lumps, 
lay  over  a  smooth  table  a  piece  of  rubber  sheeting,  lay  the  wet 
print  on  the  rubber  cloth,  face  down,  and  with  a  rubber  squeegee 
scrape  off  the  water.  Give  the  back  of  the  print,  as  it  lies  on  the 
rubber  cloth,  a  coat  of  paste,  and  then  lay  the  stretcher,  face 
down,  upon  it,  and  rub  the  muslin  into  contact  with  the  back  of 
the  print,  using  a  thin  paper-knife  to  reach  under  the  edges  of 
the  frame.  Lift  the  frame  and  rubber  cloth  from  the  table  to- 

5 


gather  and  peel  the  rubber  off  from  the  face  of  the  print.  This 
will  leave  the  print  on  the  stretcher  smooth  and  flat.  When  dry 
it  will  be  as  tight  as  a  drum  head. 

Albumenized  and  other  paper  photographs  may  be  mounted  on 
muslin  similarly.  Should  it  be  required  to  mount  them  back  to 
back  with  a  muslin  support  between  them,  trimming  had  better 
be  deferred  until  after  mounting  and  drying.  The  muslin  should, 
however,  be  well  stretched. 

To  prevent  mounted  pictures  of  large  dimensions  from  curling 
up,  the  mounts  should  be  dampened  before  the  pictures  are  laid 
upon  them.  They  are  then  dried  between  blotting-paper  and  under 
a  slight  pressure,  the  blotting-paper  being  changed  occassionally. 

To  mount  in  an  album  without  cockling,  let  the  photograph  be 
ironed  with  a  hot  iron  on  the  back  till  it  is  nice  and  smooth,  then 
place  it  under  pressure  till  quite  flat.  A  large  book  answers  the 
purpose  admirably.  To  prepare  for  mounting,  lay  the  flattened 
print  face  downwards  on  a  smooth  board  or  piece  of  glass,  and 
upon  it  place  a  piece  of  clean,  stiff  paper,  an  eighth  of  an  inch 
less  all  around  than  the  photograph,  upon  the  exposed  edge  of 
which  rapidly  and  sparely  brush  some  liquid  glue  (as  little  as 
possible)  to  cover  it,  Herein  lays  the  secret.  Avoid  making  the 
paper  wet.  The  album  being  conveniently  placed — the  position 
the  photograph  is  to  occupy  being  previously  marked  with  a  pen-  • 
cil — carefully  raise  the  photograph  with  a  point  of  some  kind;  to 
avoid  soiling  the  finger  with  the  glued  edge,  making  it  non-adhe- 
sive in  the  parts  where'  such  glue  would  be  removed,  and  lay  it 
down  in  the  proper  place.  At  once  lay  a  piece  of  clean  paper 
over  it,  and  rub  it  down  firmly  with  a  soft  rag  and  close  the 
album.  In  half  an  hour  the  face  will  be  dry  and  the  print  per- 
fectly flat,  and  it  will  remain  so. 


THE  AI.HTM. 


•CHAUTAUQUA  UNIVERSITY. 

LEWIS  MILLER.  PRESIDENT. 
J.  H.  VINCENT,  CHANCELLOR.  R.  S.  HOLMES,  REGISTRAR. 


THE 

(Jjaofenp  {Sejjool  of 

SCHOOL    HEADQUARTERS, 

423  BROOME  STREET,  NEW  YORK. 


CHARLES     WAGER     HULL. 
Supt.  of  Instruction,  C.  S.  oj  P. 


LESSON  XV. 


SPOTTING    AND    BURNISHING    THE 
PRINT. 

Spotting.— Careless  or  excessive  negative  retouching,  faults 
or  impurities  in  the  glass  supporting  the  gelatine  film,  foreign 
matter  having  accidentally  found  ingress  between  negative  and 
paper  during  printing,  dirt  upon  the  surface  of  the  negative  plate, 
and  a  variety  of  other  causes,  produce  white  spots  of  unexposed 
paper  on  albumen  prints. 

These  faults  or  spots  must  be  taken  out  or  touched  away  by 
an  operation  termed  "spotting"  by  photographers.  It  is  the 
duty  of  the  spotter  to  remove,  that  is,  to  make  invisible,  these 
white  marks. 

Simple  as  the  operation  may  appear  at  the  first  glance,  it  re- 
quires nevertheless  a  steady  hand,  an  eye  well  educated  to  judge 
correctly  of  color,  and  some  mechanical  skill.  Only  the  white 
spot  should  be  covered  with  the  retouching  medium,  and  its  color 
must  match  strictly  with  the.  general  tone  of  the  photograph.  If 
the  spot  is  large,  interrupting  different  shades,  the  touching  up  must 
be  done  in  such  a  manner  as  not  to  break  up  harmony,  or  to  pre- 
sent tones  in  variance  with  its  surroundings.  With  "blue  "  prints 
or  those  on  plain  paper  it  is  comparatively  easy  to  do  this.  Al- 
bumen paper,  on  account  of  its  gloss  and  hardness,  repels  aque- 
ous colors  and  India  ink,  and  the  print  or  color  must  be  prepared 
to  work  easily  on  the  paper. 

Take 

Gum  arabic 10  parts. 

Glycerine   1 

Alcohol 5      " 

Water 34      " 

Dissolve  the  gum  in  a  mortar  by  rubbing  it  up  well  with  the 
solvent,  add  the  other  ingredients,  mix  well,  and  keep  in  a  well- 
stoppered  bottle. 


Take  further  a  half-part  of  dried  and  pulverized  oxgall  and 
mix  well  with  ten  parts  of  the  above  solution. 

A  mixture  of  neutral  tint,  carmine  and  Prussian  blue  can  be 
made  to  match  any  photographic  tone.  Such  a  mixture  com- 
bined with  the  oxgall  preparation  is  eminently  useful  for  re- 
touching or  spotting  out  albumenized  paper  prints  A  fine  cam- 
el's-hair  brush  slightly  moistened  with  the  color  solution  will  do 
the  work.  For  larger  spots  washing  may  be  employed,  but  it  is 
better  to  do  the  work  by  stippling. 

Bromide  prints  are  best  spotted  with  a  very  soft  lead  pencil, 
Faber's  BBB. 

BURNISHING.— The  very  high  polish  on  photographs, 
now  so  popular,  is  attained  by  propelling  the  picture  over  the 
heated  burnishing  tool,  a  little  machine  constructed  especially  for 
the  purpose. 

The  burnishing  tool  should  be  uniformly  heated,  and  it  is  done 
either  with  two  or  three  alcohol  flames,  or  with  gas  passing 
through  a  perforated  tube,  which  is  attached  to  the  ordinary  gas- 
burner  by  means  of  a  rubber  tube.  Petroleum  or  oil  lamps  must 
never  be  used,  as  by  any  imperfect  combination  of  the  fuel,  car- 
bon is  separated  in  the  shape  of  smoke  or  soot,  which  will  soil 
the  picture  and  the  hands  of  the  manipulator. 


Preparatory  to  burnishing,  the  mounted  dried  and  spotted 
print  is  lubricated,  to  promote  its  free  and  uninterrupted  passage 
over  the  tool.  This  is  done  by  rubbing  over  its  face  an  alcoholic 
solution  of  Venetian  or  Castile  soap,  or  finely  scraped  solid  soap. 

A  print  to  be  burnished  should  not  be  dried  too  much,  as  the 
swell  of  the  card  bends  the  picture  backwards.  Let  the  picture 
dry  until  the  contraction  of  the  paper  just  commences  to  bend 
the  picture  forwards.  It  will  be  found  that  the  picture  in  this 
stage  is  about  three-fourths  dry,  and  it  is  absolutely  necessary 
that  it  should  not  be  allowed  to  dry  any  more  than  this  until  after 
it  has  gone  through  the  burnisher. 

This  is  best  done  by  arranging  the  pictures  in  one  or  two  piles, 
and  placing  them  under  a  weight.  They  should  be  carefully 
taken  from  the  pile  and  spotted  out,  and  immediately  placed  in 
another  pile  under  a  weight.  The  same  precaution  should  be 
taken  in  applying  the  lubricator  to  the  print.  The  reason  for  this 
method  of  procedure  will  be  evident  to  anyone  who  has  observed 
with  what  a  number  of  irregular  lines  the  surface  of  a  picture  be- 
comes broken  when  allowed  to  become  perfectly  dry  in  the  usual 
manner.  When  these  checks  have  once  appeared  in  a  picture, 
there  is  no  method  of  again  uniting  the  broken  surface.  When 
burnished  by  the  above  directions,  the  picture  will  be  found  to 
be  very  compact  and  hard  when  cool,  and  neither  alcohol  nor 
water  will  destroy  the  gloss  thus  obtained.  It  is  advisable  to  put, 
first,  the  picture  through  the  burnisher  lengthways,  curling  it  up 
backwards  around  the  roller,  afterwards  put  it  through  sideways, 
thus  straightening  it,  and  thereby  a  much  higher  polish  will  be 
secured. 

If  occasionally  a  cabinet  or  card  picture  will  not  take  the  gloss, 
breathe  upon  it  freely  before  running  it  through  the  burnisher. 
Should  the  enamel  not  be  produced  the  first  time,  repeat  the 
operation  after  the  picture  has  become  cool  ;  the  desired  result 
will  then  be  obtained. 

It  is  imperative  to  keep  the  burnishing  tool  in  a  good  condi- 
tion. Rust  or  scratches  are  its  greatest  enemy,  and  if  they  should 
occur,  a  repolish  can  be  given  to  the  burnisher  by  rubbing  it  well 
with  an  oiled  leather  file  and  the  finest  emery  flour. 

Unmounted  photographs   are   often  required  to  be  burnished. 

The   trimmed  and    spotted  picture   is  lubricated  as  usual,   laid 

smoothly  upon  an  ordinary    card-board,  larger  than  the  print, 

just  in  the  same  position  as  if  it  had  been  mounted  thereon,  and 

5 


passed  over  the  tool.  The  manipulation  does  not  differ  from 
that  of  mounted  prints,  but  care  must  be  taken  not  to  allow  the 
print  to  slip  from  its  position. 

When  mounted  on  muslin,  the  burnishing  of  prints  is  quite 
easy,  but  it  is  advisable  to  place  a  card-board  between  the  rough 
roller  and  the  print,  so  as  to  prevent  an  impression  of  the  corru- 
gated surface  of  the  muslin.  When  burnishing  prints  that  are 
mounted  back  to  back,  either  with  or  without  paper,  or  muslin 
support  between  them,  the  card-mount  protector  must  also  be 
employed,  burnishing  the  one  side  of  the  double  print  first,  then 
the  other  in  the  usual  manner.  Often  pictures  are  seen  present- 
ing a  much  higher  and  more  beautiful  gloss  than  can  be  obtained 
with  the  burnisher.  These  are  called  "enamels"  or  "glaces." 
The  method  of  enamelling  is  a  little  more  complicated,  but  nev- 
ertheless is  quite  easy.  It  is  done  in  the  following  manner  : 

ENAMELLING. — Sprinkle  the  surface  of  a  glass  plate 
with  powdered  French  chalk,  rub  it  evenly  over  the  surface  with 
a  tuft  of  cotton  wool,  continuing  to  lightly  rub  it  until  the  chalk 
is  all  removed,  then  coat  the  glass  with  the  following 

COLLODION  : 

Soluble  gun  cotton 48  grains. 

Alcohol 4  ounces. 

Sulphuric  ether 4  ounces. 

As  soon  as  the  collodion  is  well  set  lay  upon  it  the  print,  pre- 
viously soaked  in  a  warm  solution  of  one-half  ounce  gelatine  in 
ten  ounces  of  water,  to  which  a  few  drops  of  glycerine  have  been 
added.  Expel  all  air  bubbles  from  beneath  the  print  and  squee- 
gee it  into  absolute  contact  with  the  collodionized  glass. 

After  drying,  the  print  can  be  peeled  off  from  the  glass  and  the 
face  will  present  a  polish  almost  as  high  as  the  surface  of  the 
glass  from  which  it  has  been  removed.  The  print  is  then  ready 
to  mount,  as  follows  :  Moisten  the  face  of  the  mount  with  a  damp 
sponge  and  lay  upon  it  the  pasted  print ;  rub  down  with  a  soft 
cloth  and  put  under  pressure  to  dry. 

The  addition  of  five  per  cent,  of  glycerine  to  the  paste  will  pre- 
vent the  print  peeling  off  the  glass  as  it  dries. 

For  enameling  bromide  prints  the  same  collodion  substratum 
as  mentioned  above  may  be  employed. 

As  soon  as  the  collodion  is  well  set,  slide  the  plate  face  up  into 
a  tray  of  water,  in  which  is  floating,  face  down,  the  permanent 
bromide  print,  which  has  just  been  fixed  and  washed  ;  grasp  the 

6 


plate  and  print  by  one  end  and  lift  together  from  the  water, 
avoiding  bubbles  and  draining  the  water  from  the  opposite  end  ; 
squeegee  the  print  into  contact  with  the  plate  and  set  away  to 
dry.  Before  the  print  is  quite  dry  apply  a  coat  of  starch  paste 
to  the  back. 

Another  method  is  to  squeegee  the  wet  print,  face  down,  on  a 
polished  piece  of  hard  rubber  or  ebonite  ;  when  dry  the  print 
will  peel  off  with  a  fine  polished  surface.  The  print  should  be 
slipped  on  to  the  rubber  plate  under  water  to  avoid  air  bells. 

Cyanotypes  and  plain  paper  photographs  do  not  assume  gloss 
so  readily  under  the  burnisher  as  do  albumen  prints,  but  they  too 
may  be  enameled  to  a  considerable  extent. 

Great  richness  of  tone  and  depth,  transparency  and  detail  in 
lights  and  shadows  can  be  given  to  them  with  encaustic  paste  ; 
securing  also  their  permanency  thereby,  this  paste  being  a  pre- 
ventative  against  the  action  of  moisture  and  injurious  gases. 

The  formula  for  the  paste  is  as  follows  : 

Pure  virgin  wax 500  grains. 

Gum  elemi 10 

Benzole 200       " 

Essence  of  lavender 300 

Oil  of  spike 15 

Melt  the  whole  on  a  water  bath  thoroughly,  and  strain  through 
muslin.  A  simpler  plan  is  to  dissolve  the  elemi  in  the  solvents 
as  described,  and  after  filtering,  mix  with  the  melted  wax,  as  the 
filtration,  which  is  chiefly  intended  for  the  gum  elemi,  is  more 
easily  managed  before  the  wax  is  present.  This,  when  finished, 
forms  a  stiff  paste.  By  increasing  the  proportion  of  essence  of 
lavender,  it  can  be  made  thinner,  which  in  winter  may  be  desir- 
able. The  encaustic  paste  is  put  on  the  print  in  patches  in  three 
or  four  parts,  and  then  rubbed  with  a  light,  quick  motion,  with  a 
piece  of  clean  flannel,  until  a  firm,  fine  surface  is  obtained.  If  a 
rich,  thick  coating  of  the  encaustic  be  desired,  a  very  light  pres- 
sure in  rubbing  is  necessary,  so  that  a  polish  may  be  acquired 
without  rubbing  off  the  paste  in  the  operation.  If  a  print  is  re- 
touched, more  care  must  be  taken  to  use  the  hand  lightly  in 
applying  the  paste. 

Finishing  a  photograph  properly  is  of  as  much  importance  as 
the  developing  or  printing  of  it.  A  badly  mounted,  spotted  or 
burnished  picture  may  spoil  all  the  good  work  previously  done, 
and  the  tyro  must  therefore  never  neglect  to  give  the  final  manip- 
ulation his  undivided  and  careful  attention. 

7 


CHAUTAUQUA  UNIVERSITY, 

LEWIS  MILLER.  PRESIDENT. 
j.  H.  VINCENT,  CHANCELLOR.  R.  5.  HOLMES,  REGISTRY 


THE 


{fcjjool  of  PholiographJ, 


SCHOOL    HEADQUARTERS, 

423  BROOME  STREET,  NEW  YORK. 


CHARLES    WAGER     HULL 
Supt.  of  Instruction,  C.  S,  of  P. 


LESSON  XVI. 

Portraiture. 

THIS  important  and  most  difficult  branch  of  photography  can 
hardly  receive  sufficient  attention  within  the  short  space  of  a 
Chautauqua  lesson.  A  mere  outline  only  can  be  given  to  the  student 
in  describing  the  construction  of  the  studio,  or  the  uses  of  back- 
grounds and  accessories,  the  lighting  and  posing  of  subject,  or  the 
arrangement  of  groups,  although  this  should  be  considered  in 
more  detailed  form.  It  is  impossible  to  give  concisely  all  that 
upon  which  innumerable  artists  have  written  volumes  with  more 
or  less  success. 

Before  any  degree  of  proficiency  can  be  attained,  art-photog- 
raphy requires  much  practical  exercise,  close  observation,  and 
diligent  reading.  The  superintendent  and  instructor  of  the 
School,  therefore,  urgently  advise  that  the  study  of  this  lesson  be 
followed  by  that  of  a  good  book  on  the  subject.* 

*The  Studio,  and  What  to  Do  In  It.  By  H.  P.  Robinson  (Scovill 
Manufacturing  Co.  Price,  15  cents). 

1 


The  studio  or  skylight  room  must  be  of  first  consideration.  It 
is  well  to  have  plenty  of  space  to  move  about  in  and  to  contain 
the  necessary  furniture,  apparatus  and  accessories.  The  length 
may  be  partly  determined  by  the  size  of  the  pictures  intended  to 
be  made,  and  it  will  be  found  that  if  the  room  is  to  be  long 
enough  to  allow  a  cabinet  portrait  to  be  taken  of  a  full  length 
standing  figure  with  sufficient  space  for  background,  camera  and 
contingencies,  twenty-eight  feet  will  be  quite  sufficient.  In 
width,  if  we  allow  enough  space  for  furniture,  head-rests,  addi- 
tional cameras  and  utensils,  fourteen  feet  will  give  room  enough 
to  work  comfortably  in. 

Various  opinions  exist  among  experts  as  to  the  best  shape  and 
position  of  the  skylight.  There  are  certain  rules  and  facts,  how- 
ever, which  should  not  be  disregarded.  Contrast  between  light 
and  shade  is  a  point  of  the  utmost  importance,  and  the  results 
deriving  from  their  management  are  obvious.  If  all  the  light 
comes  from  one  point,  the  contrast  will  be  too  violent,  whereas 
two  lights,  equally  strong  from  opposite  directions,  would  place 
the  subject  to  disadvantage,  destroy  contrasts,  produce  flat  pic- 
tures, without  roundness  and  solidity  in  the  effect.  The  light 
thrown  on  the  subject  should  be  diffused  and  soft.  The  direct 
light  of  the  sun  must  be  avoided.  It  is  well  to  remember  that, 
if  the  skylight  faces  east,  the  rising  sun  will  stream  in;  a  southern 
light  admits  the  sun  immediately  before  and  after  noon,  while  a 
western  light  is  equally  objectionable  on  account  of  the  afternoon 
sun.  It  is  only  from  the  north,  then,  that  the  sunlight  can  be 
avoided  ;  hence  every  skylight  should  face  the  north. 

It  must  be  borne  in  mind  that  a  skylight  suitable  for  one  style 
of  work  is  not  always  the  best  for  another  class.  Thus  a  low 
light  is  generally  better  for  standing  or  entire  figures,  and  gives 
brilliancy  to  all  parts  of  the  picture,  while  a  higher  light  is  better 
suited  for  head  and  bust  pictures,  it  being  softer  and  more  sub- 
dued. Therefore,  it  is  an  essential  point  to  so  construct  a  sky- 
light as  to  adapt  it  as  near  as  may  be  to  the  producing  of  general 
work.  When  it  is  impracticable  to  have  a  side  light,  the  top 
light  should  have  considerable  slope,  and  thus  give  different 
heights,  but  when  it  is  practicable,  top  light  should  be  combined 
with  a  side  light.  The  side  light  should  rise  in  an  elevation  from 
thirty  to  thirty-five  inches  above  the  floor,  be  not  less  than  six 
feet  and  not  more  than  eight  feet  high,  and  not  less  than  fen  feet 
and  not  more  than  twelve  feet  long.  The  top  light,  rising  from 
the  side  light  in  an  angle  of  thirty-five  degrees,  should  be  of  the 
same  length  as  the  side  light,  or  one-fourth  more. 

2 


At  certain  periods  of  the  year,  when  the  sun  stands  at  a  high 
elevation,  its  rays  will  be  apt  to  intrude  themselves  through  the 
top  light,  to  avoid  which  to  a  certain  extent  two  poles  may  be 
erected,  furnished  with  cross  bars,  along  which  a  canvas  curtain 
may  be  drawn. 

The  sashes  should  be  glazed  with  white  glass,  and  the  panes 
be  as  large  as  practicable  to  avoid  too  often  repeated  lappings. 

To  regulate  light  effects  at  the  will  of  the  operator,  to  concen- 
trate it  in  some  points,  to  exclude  it  or  subdue  it  in  others,  we 
resort  to  movable  screens  or  shutters.  A  plan  to  be  recommended 
is  to  provide  two  or  three  shades  on  spring  rollers,  whose  com- 
bined widths  are  the  width  of  the  top  light,  the  spring  rollers 
being  attached  to  the  highest  point  of  the  top  light.  These  may 
be  made  of  some  stiff  material,  and  of  a  light  neutral  color  ;  and 
if  a  double  set  of  curtains  is  preferred,  the  other  can  be  of 
thin  white  muslin.  The  side  light  may  be  curtained  similarly, 
but  movable  from  side  to  side. 

The  color  of  the  interior  of  the  studio  had  also  best  be  of  a 
light  neutral  tone.  The  floor  should  be  level  and  steady  ;  it 
may  be  painted  of  a  light-brown  or  other  suitable  color. 

Carpets  and  oilcloth  are  objectionable  for  several  reasons. 

Backgrounds  are  essential  parts  of  the  studio,  and  should  be 
properly  selected.  If  plain  and  uniform  in  tone,  the  effects  pro- 
duced by  them  are  plain  and  uniform.  A  carefully  graduated 
background  relieves  certain  parts  of  the  picture,  and  contrasts 
well  with  others ;  thus  the  lights  in  the  figure  should  be  relieved 
by  the  darker  shades  in  the  background,  and  vice  versa.  Fancy 
painted  backgrounds  are  always  a  dangerous  experiment,  except 
in  the  hands  of  an  expert.  Asolutely  avoid  heavy  columns, 
pedestals  or  balustrades  ;  they  rarely  contribute  to  the  beauty  of 
the  picture.  The  introduction  of  a  gracefully  falling  curtain, 
with  good  taste  and  in  keeping  with  the  subject,  may  occasionally 
be  permitted  to  relieve  what  otherwise  might  appear  too 
monotonous,  or  to  form  a  balance  line,  which  might  be  requisite. 

In  the  introduction  of  accessories,  such  as  rocks,  stumps,  gate- 
ways, shrubbery,  etc.,  these  should  be  faintly  but  distinctly  re- 
produced to  give  life  and  harmony  to  the  background,  represent- 
ing a  landscape  or  garden  scene,  with  graduated  sky  of  delicate 
and  broken  clouds. 

For  interiors,  the  background  might  be  in  panels  of  graduated 
tints  ;  if  painted  to  represent  the  light  streaming  in  from  a  case- 
ment, be  very  careful  that  the  light  falls  on  the  sitter  from  the 
same  direction. 


The  nearer  the  subject  is  to  the  light  the  stronger  will  be  the 
shadows.  A  reflecting  side  screen  will  subdue  excessively  strong 
shadows  on  the  face.  It  should  be  covered  with  very  light-gray 
material,  and  be  placed  obliquely  towards  the  sitter,  and  at  a 
distance  to  soften  the  shadows,  but  not  near  enough  to  destroy 
them  entirely. 

How  to  light  the  sitter  can  be  treated  in  general  terms  only. 
Lighting  the  subject  in  general  and  special  cases  is  a  question 
which  can  be  solved  by  the  operator  alone  when  the  subject  is 
before  him.  He  must  see  that  light  and  shade  fall  so  as  to  pro- 
duce the  most  agreeable  effect  before  the  sensitive  plate  is  ex- 
posed, and  with'  the  capacity  of  seeing  this,  the  power  of  modi- 
fying is  usually  accompanied. 

As  a  general  principle,  a  high  side  light  a  little  in  advance  of 
the  sitter  is  the  best  direct  light ;  excess  of  vertical  light  is  in 
most  cases  to  be  avoided  ;  nevertheless,  it  may  be  useful  at  times 
in  giving  form  and  brilliancy  to  flat  commom-place  faces.  But 
where  the  sitter  has  heavy  brows,  sunken  eyes,  or  prominent 
features,  the  least  possible  vertical  light  should  be  employed,  or 
these  features  will  look  more  marked  and  heavy.  With  such 
faces  the  side  light,  well  in  advance  of  the  sitter,  will  give  the 
most  soft  and  harmonious  effect  without  risk  of  flatness.  The 
top  front  light  will  generally  serve  to  illumine  sufficiently  the 
shadow  side  of  the  face  without  having  to  resort  to  the  reflecting 
side  screen,  which,  however,  under  some  circumstances,  will  not 
only  be  useful  but  necessary.  As  a  rule,  a  mild  and  soft  light  is 
what  is  required.  Strong  illumination  produces  light  and  shad- 
ows of  much  intensity,  giving  black  and  white  pictures. 

There  are  other  influences  besides  the  amount  of  space  through 
which  light  is  admitted.  The  aspect  of  the  day,  the  period  of 
the  year,  the  quality  of  light,  the  situation  of  the  studio,  and  the 
quality  of  the  plate  ;  for  a  very  sensitive  plate  seems  to  require 
a  greater  contrast  of  light  and  shade  than  a  slow  one. 

The  true  test  of  good  lighting  is  roundness.  This  can  only  be 
got  by  securing  delicacy  in  the  half  tones,  there  should  be  no 
broad  patches  of  light  and  shade,  but  gradation  everywhere. 
The  operator  must  educate  himself  to  see  these  half  tones  and  he 
must  see  them  in  his  model  without  looking  at  the  ground  glass. 
Get  the  right  effect  in  nature  and  the  rest  will  follow. 

A  few  remarks  on  the  imperfections  of  the  human  face  might 
now  be  appropriate. 

Every  face  has,  artistically  speaking,  two  distinctly  different 
sides,  and  it  is  for  the  operator  to  select  for  a  portrait  the  best 

4 


view.  With  gentlemen,  as  a  general  thing,  the  hair  is  parted  on 
one  side,  and  that  side  is  usually  preferred,  if  there  be  no  reason 
for  doing  the  reverse.  Often  the  head  is  rather  bald  towards  the 
beginning  of  the  parting  ;  in  such  cases  perhaps  the  opposite 
side  would  be  preferrable.  Light  yellow  or  red  hair  should  be 
powdered,  unless  a  color  sensitive  plate  is  to  be  exposed. 

In  cases  of  a  too  high  forehead,  the  latter  may  be  foreshort- 
ened by  raising  the  camera.  Blue  and  light  eyes  should,  as  a 
general  rule,  be  turned  from  the  light.  Deeply  sunken  eyes  re- 
quire considerable  front  and  very  little  top  light.  Where  the  eye 
is  defective,  you  will,  of  course,  turn  that  side  •  away  from  the 
camera  as  much  as  is  necessary,  to  lose  sight  of  the  defect  ;  or 
even  a  profile  may  be  taken.  Where  one  eye  is  smaller  than  the 
other,  it  is  generally  preferrable  to  take  the  larger  more  promin- 
ently. Where  one  eye  is  higher  than  the  other,  if  no  other  ob- 
jection offer,  take  the  higher  eye.  In  the  case  of  small  and  par- 
tially closed  eyes,  make  them  look  upwards,  or  if  desired  that  the 
portrait  look  at  you,  depress  the  chin  a  little.  For  very  large 
and  staring  eyes  make  them  look  lower. 

In  a  full  face  the  eyes  may  look  straight  forward,  being  careful 
to  turn  the  body  to  one  side  more  or  less ;  never  have  chest  and 
head  presented  perfectly  full  to  the  camera. 

The  direction  of  the  eyes  is  important.  Never  allow  the  head 
to  turn  in  one  direction  and  the  eyes  in  the  opposite  ;  nothing  can 
be  worse  than  this.  If  the  head  be  turned  to  the  right,  make  the 
eyes  turn  a  trifle  more  so  in  this  direction  ;  when  the  head  turns 
to  the  left,  turn  the  eyes  also  a  trifle  more  in  the  same  direction. 
In  the  case  of  short-sighted  persons  wearing  spectacles,  beware 
of  false  reflections.  An  improperly  placed  side  screen  will  re- 
flect so  much  light  that  the  eyes  are  perfectly  obliterated. 

In  but  very  rare  cases  do  we  find  a  perfectly  straight  nose.  If 
it  turn  to  the  left  or  right,  the  two  sides  of  the  face  will  appear 
materially  different ;  when  twisted  towards  the  left,  and  a  view 
taken  from  that  side,  it  will  shorten  the  nose  apparently,  whereas 
the  opposite  result  takes  place  from  the  other  side.  If  the  nose 
be  very  long  take  the  face  rather  full.  In  the  case  of  a  turned 
up  nose,  raise  the  camera  as  high  as  possible,  to  avoid  looking  up 
the  nostrils  ;  with  a  round  and  rather  flat  or  fat  nose,  take  it 
pretty  well  from  the  side. 

For  high  cheek  bones  with  hollow  cheeks,  be  very  careful  of 
too  strong  top  light,  and  take  the  face  rather  full,  well  lighting 
up  the  cheeks.  In  frequent  cases  the  profile  is  the  better  view. 

5 


Should  one  cheek  be  swollen,  perhaps  it  would  be  better  to  avoid 
that  side ;  if  not  practicable  to  do  so,  rest  the  cheek  upon  the 
hand. 

Old  and  wrinkled  faces  require  a  strong  front  light  without 
much  shadow,  and  are  generally  best  taken  in  full  front  views. 

Small  and  narrow  mouths  may  be  taken  rather  full,  pursue  the 
opposite  course  with  large  mouths  and  fat  lips. 

It  is  very  difficult  to  secure  pictures  of  large  open  mouths  with 
protruding  teeth.  Closing  the  lips  by  force  distorts  the  chin  and 
all  chance  of  obtaining  a  good  likeness  is  lost.  Engage  the  sitter 
in  conversation  and  expose  the  plate  when  mouth,  chin  and 
cheeks  are  in  the  most  favorable  position. 

Full  or  three-quarter  length  figures  are  more  difficult  to  man- 
age than  a  head  and  bust.  A  pictorial  background  may  then  be 
employed,  and  furniture  or  other  accessories  appropriate  to 
background  and  the  costume  of  the  sitter  are  admissible. 

For  a  lady  there  is  nothing  better  than  a  simple  attitude,  with- 
out attempting  to  pose  artificially  ;  let  the  hands  join  in  front,  or, 
for  variety's  sake,  rest  one  upon  a  chair  or  other  suitable  piece 
of  furniture.  Throwing  one  hand  behind  the  back  gives  in  some 
positions  very  pretty  effects.  When  furniture  is  used  to  assist  in 
making  the  position,  a  piece  of  lace  or  nicely  folded  drapery  is  of 
great  value  to  conceal  some  parts  or  bring  others  into  better  re- 
lief. Sitting  figures  are  more  easily  posed  than  standing  ones  ; 
more  action  can  be  brought  into  the  picture,  and  employment  be 
given  to  the  hands,  thus  obtaining  life  and  expression  for  the 
whole  composition.  A  fan  lends  itself  admirably  to  the  purpose, 
so  does  a  book,  sewing,  writing,  or  similar  employment. 

No  difficulty  occurs  with  greater  force  in  portraiture  than  the 
posing  of  hands.  Arms  and  hands  should  be  rather  retired,  both 
in  position  and  tone  ;  if  they  must  come  in  the  picture,  endeavor 
to  turn  the  edge  of  the  hand  towards  the  camera,  and  avoid 
leaning  the  arms  to  heavily  against  anything  which  will  distort 
the  natural  form.  Care  should  be  taken  that  the  fingers  curve 
gracefully  and  the  hands  do  not  look  like  claws.  Hands  appear 
frequently  too  large,  and  to  prevent  that  they  must  be  placed  in 
a  plane  with  the  face.  In  some  positions  a  hand  looks  much 
larger  than  in  others,  especially  so  when  its  broad  back  is  seen. 
When  the  fingers  are  interlaced  the  effect  is  similar. 

A  well-formed  hand  is  a  beautiful  object,  and  while  in  the 
composition  of  a  portrait,  first  consideration  is  given  to  the  head 
as  the  principal  object,  the  second  place  the  artist  must  neces- 
sarily give  to  the  hands. 


Group  pictures  are  likewise  not  easily  made,  and  none  present 
as  many  difficulties  as  the  family  group,  in  which,  frequently, 
three  generations  are  represented,  offering  thus  material  of  vari- 
ous kinds,  from  which  to  compose  a  whole,  harmonious  in  all 
respects.  It  is  in  all  cases  demanded  that  each  individual  of  a 
group  gives  an  equally  well-lighted  portrait  and  perfect  likeness, 
and  while  one  of  the  first  art-principles  and  good  taste  tell  us 
that  one  or  more  of  the  component  parts  of  a  picture  should  be 
given  prominence,  and  others  be  subdued  in  light-effect,  a  variety 
of  difficulties  must  naturally  occur.  Groups  should  always  be 
arranged  in  pyramidal  form,  and  in  such  a  manner,  that  the  tout 
ensemble  appears  to  be  composed  of  several  minor  pyramids. 
The  same  refers  to  smaller  groups  of  but  a  limited  number  of 
persons.  For  two,  let  one  stand,  the  other  sit  ;  while  in  a  group 
of  three,  two  had  better  be  sitting  and  one  standing  By  no 
means  should  the  persons  composing  a  group  stare  at  the  camera; 
let  every  one  of  them  select  a  point  to  look  at,  according  to  the 
turn  of  the  head,  and  on  a  level  with  the  eye. 

Out-door  groups  frequently  represent  a  mass  of  figures,  without 
any  attempt  of  artistic  arrangement.  This  latter  disposition  is 
caused  by  the  impossibility  of  getting  assistance,  from  the  nature 
of  the  ground  or  place,  where  the  photograph  is  taken  ;  but  it  is 
the  operator's  task  to  utilize  to  best  advantage  the  material 
offered.  He  should  look  out  for,  and  take  advantage  of,  any  spot 
that  would  afford  him  aid  to  break  up  monotony,  and  to  give 
variety  to  the  general  form.  A  picturesque  set  of  steps  gives 
such  aid  to  a  high  degree.  More  tasty  appear  groups,  when  a 
motive  for  the  gathering  of  many  persons  is  represented  in  the 
picture  ;  prominence  should  be  given  to  the  most  important  per- 
sons, and  action  thrown  into  each  individual  and  the  whole. 

In  selecting  a  background,  it  should  be  endeavored  to  secure 
one  with  a  broad  expanse  of  light,  if  not  too  blank.  Much  detail 
is  objectionable,  as  it  interferes  with  the  figures.  The  worst 
background,  but  the  one  that  is  oftenest  used  for  out-door  groups, 
consists  of  foliage  of  large,  shining  leaves.  The  effects  of  the 
white  spots  caused  by  the  glittering  leaves,  especially  when  out  of 
focus,  is  very  disagreeable. 

The  introduction  of  animals  is  in  most  cases  objectionable. 
A  cat  or  a  dog  have  often  totally  spoiled  an  otherwise  quite  per- 
fect group. 

The  photographing  of  children  was,  with  the  old  slow  pro- 
cesses, the  bete  noir  of  the  operator.  Thanks  to  the  rapid  emul- 
sion plate,  the  small  members  of  society  are  comparatively  quite 

7 


easily  managed  now.  Posing  and  lighting  them,  however,  re- 
quires, under  all  circumstances,  much  patience  and  perseverance, 
a  tranquil  mind,  and  a  certain  self-possession,  which,  unfortu- 
nately, are  not  always  displayed  by  the  operator,  when  a  young 
babe  is  placed  before  his  camera. 

To  make  portraits  with  our  own  limited  amateur  outfits,  and  in 
our  own  homes,  with  the  command  of  light  emanating  from  one 
window  only,  is  easily  accomplished.  Place  your  sitter  at  an 
oblique  angle  toward  the  one  window  of  the  room,  allowing  its 
full  force  of  light  to  illuminate  the  subject.  To  avoid  a  con- 
fusion of  light-effects,  screen  the  other  window  or  windows,  with 
a  white-muslin  shade  or  tissue  paper,  by  which  means  harmony 
is  established,  and  sufficient  illuminating  force  secured.  If  the 
shadows  cast  are  too  abrupt  or  too  opaque,  reflect  light  from  the 
opposite  side  ;  a  clothes-horse,  covered  with  a  sheet  or  table-cloth, 
answers  quite  well  for  the  purpose.  Our  single  achromatic  lenses, 
with  which  we  have  learned  to  make  landscapes,  require  a  long 
time  of  exposure,  to  make  portraits  in  an  ordinarily-lighted  room. 
Still,  a  few  seconds  only  are  needed  when  a  Carbutt  special,  or 
"lightning"  plate  is  to  be  exposed,  while  the  "B,"  our  favorite 
for  timed  landscape  work,  would  require  from  ten  to  fifteen,  and, 
in  most  cases,  probably  even  more  seconds. 

For  photographic  portraiture,  a  different  kind  of  lens  is  con- 
structed, possessing  more  luminous  power,  and  consequently 
working  more  rapid  than  the  single  landscape  lens.  Of  these 
however,  we  will  treat  in  the  lesson  on  lenses. 


CHAUTAUQUA  UNIVERSITY. 

LEWIS  MILLER,  PRESIDENT. 
J.  H.  VINCENT,  CHANCELLOR.  R.  S.  HOLMES,  RBGISTKAI 


TH  E 


dfjaulsaiiqiia  $cljool  of 


SCHOOL    HEADQUARTERS, 

423  BROOME  STREET,  NEW  YORK. 


CHARLES     WAGER     HULL, 
Supt.  of  Instruction,  C.  5.  oj  P. 


LESSON  XVII. 


RETOUCHING   THE    NEGATIVE. 

NEGATIVES  of  portraits,  and  in  frequent  cases  of  landscapes,  too, 
require  certain  corrections  before  satisfactory  prints  can  be  made 
from  them.  In  faces  there  are  wrinkles  and  heavily  shaded  folds 
to  be  subdued,  warts  or  scars  to  be  removed,  freckles  obliterated, 
broad  shadows  lightened,  and  very  often  whole  features  to  be 
remodelled.  In  landscapes,  we  also  assist  with  pencil  and  brush 
to  establish  better  harmony  ;  we  lighten  up  shadows,  correct 
broken  lines,  add  or  remove  objects,  either  wanted  in  the  picture 
or  objected  to,  introduce  high  lights,  strenghten  up  distances, 
and,  when  practical,  introduce  a  clouded  sky. 

It  is  the  function  of  the  retoucher  to  improve  negatives  by 
judicious  and  careful  work,  to  give  them  artistic  effects  when 
wanted,  but  not  to  overdo  his  task  and  merely  smooth  the  plate 
down  mechanically,  like  the  joiner  planes  down  a  board.  Re- 
touching must  be  done  well,  if  the  effects  aimed  at  cannot  be 
reached,  it  will  be  far  better  to  print  from  an  unretouched  plate, 
with  all  the  objectionable  features  in  it/UThe  retoucher  should 
be  a  photographer  ;  that  is,  he  should  be  able  to  judge  of  the 
quality  of  the  negative  to  enable  him  to  know  where  to  employ 
the  pencil  and  where  not.  He  can  make  a  work  of  art  from  an 
average  good  negative,  but  he  will  never  be  able  to  render  a  posi- 
tively bad  negative  serviceable  for  printing.  Retouching  is  an  aid 
in  photography,  but  should  never  be  considered  of  main  im- 
portance when  making  negatives  ;  nor  should  the  operator  rely 
upon  the  pencil  to  supply  wants  that  plate  and  camera  have  re- 
fused to  give. 

Therefore,  it  cannot  be  laid  down  too  clearly  that  retouching, 
even  when  done  by  a  real  artist,  should  be  considered  only  as  a 
necessary  continuation  of  very  careful  work  ;  not  that  the  part 
of  the  retoucher  is  inferior  to  that  of  the  operator,  but  that  the 
two  should  work  so  well  together  that  the  final  result  will  be  ar- 
rived at  through  the  cleverness  of  both. 
3 


f  It  is  not  everybody  who  can  retouch  well  _jjHs  a  wnrk  requiring 
a  great  deal  j3f_tast£,_  lightness  of  hand,  close  application,  and 
great  patience.dl  of  which  qualities  few  people  possess.  But 
every  photographer  is  capable  of  correcting  in  his  negatives  some 
faults  which  may  occur,  no  matter  how  skilled  the  operator 
may  be. 


materials  Necessary  for  Negative  Retouching. 

The  first  thing  wanted  is  an  easel  on  which  to  work.  This 
should  be  a  piece  of  fine  ground  glass  in  a  frame,  on  which  the 
negative  is  placed.  The  bottom  of  this  frame  has  hinges  as  well 
as  the  top,  which  retain  a  cover  of  wood  kept  open  by  means  of 
small  supports,  which  are  lying  on  the  sides  of  the  frame  of  the 
ground  glass.  The  necessary  slant 
is  given  to  this  by  means  of  two 
other  supports,  entering  at  will  into 
some  notches  on  the  edges  of  the 
surface  of  a  flat  and  square  box,  of 
which^  the  middle_is— covered  by  a 
ooking  glass  reflecting  the  ligh t 
under  the  neffiiivp  Several  car- 
riers, same  size  as  the  ordinary 
photographic  glasses,  and  fitting 
one  into  the  other,  stop  completely 
the  light  round  the  negative,  f  A 
little  movable  rule  gpes  up  ana  down  in  front  of  the  ground 
glass,  and  serves  as  a  rest  for  the  hand  of  the  retoucher.  }  This 
easel  should  be  put  upon  a  table  before  a  window  with  a  north 
aspect.  As  there  should  be  no  light  except  what  illuminates  the 
negative,  a  black  blind  should  be  thrown  over  the  top,  and  to  fall 
down  each  side.  There  are  easels  sold  on  purpose,  and  provided 
even  with  wooden  shutters,  which  are  kept  open  by  hooks  fitting 
into  the  top  shutter.  The  retoucher  is  thus  inclosed  in  a  box, 
nd  gets  no  light  except  what  comes  through  the  negative. 

The  choice  of  pencils  and  brushes  is  very__important,  and  we 
may  now  describe^  the  pencils  to  be  used — the  great  desideratum 
being  one  with  pltmugh  texture,  and  capable  of  taking  a  fine,  hard 
point.  Such  a  one  is  the  best  octagonal  black-lead  pencils  of 
Faber,  which  in  contrast  with  many  are,  as  a  retoucher  once  ob- 
served to  us,  "  almost  capable  of  doing  the  retouching  them- 
selves." 


It  is  desirable  to  have  three  or  four  different  degrees  of  hard- 
ness of  pencil,  so  as  to  suit  every  cjasg  of  work,  the  HH,  H,  F, 
and  HB  being  the  most  suitable.  Trhe  H  is  for  general  work  ; 
the  HH  (the  hardest  of  the  four),  forve?y  fine  and  delicate  execu- 
tion and  where  little  labor  is  required.  The  F  and  HB  are  suit- 
able for  heavier  pencilling  when  the  shadows  are  heavy  and  con- 
siderable opacity  is  needed.  It  is  customary  to  point  them  in  a 
manner  quite  different  from  what  one  is  usually  accustomed  to. 
The  lead  is  laid  bare  to  the  extent  of  almost  an  inch,  and  a  more 
or  less  fine  point  given  to  It,  according  to  the  negative  under 
treatment. 

•^The_brushes  should  be  sable,  and  very  soft.  It  is  very  difficult 
to  get  good  brushes,  so  they  should  be  chosen  with  great  care. 
They  must  be  pretty  thick,  not  too  long,  and  with  a  very  good 
point.  All  this  will  be  easily  found  out  by  dipping  them  in 
water  and  bending  them  about.  If  a  brush,  then,  at  nnr^  msV^ 
a  fine  point,  it  is  a  good  one. 

[The  two  colors  most  required  in  negative  retouching  are  Indian 
ink  and  light  blue.  The  first  is  the  most  opaque  color,  but  as 
the^tint  is  the  nearest  to  the  negative,  it  will  permit  of  finer  work, 
"finally,  stumps  of  different  sizes,  and  a  very  soft  camel's-hair 
brush  for  dusting  the  surface  during  the  operation,  will  complete 
the  list  of  necessary  implements  for  the  retoucher. 
/  Gelatinejiegati ves  can  be  retouched  upon  without  being  var- 
/nished,  although  a  varnished  surf ace^  is  ojtenjjreferred.  In  either 
case,  the  film  requires  a  previous  preparation,  to  allow  the  pencil 
to  take.  This  is  done  by  rubbing  over  the  parts  to  be  retouched 
a  few  drops  of  the  S.  P.  C.  retouching  fluid,  either  with  the  finger 
or  a  small  tuft  of  cotton  wool.  The  fluid  should  be  rubbed  in 
well,  but  not  to  complete  dryness,  allowing  a  slight  cuticle  of  it 
to  remain,  which,  after  an  hour  or  two  will  be  dry  enough  to 
work  upon.  After  a  negative  has  been  varnished^  the  same  ap- 
plication  can  be  made,  provided  the  yarnisj^is  dry. 

The  method  of  deadening  the  varnish  gloss  by  rubbing  over  it 
finely-powdered  cuttle-fish  bone  has  been  entirely  abandoned,  as 
upon  such  surface  the  pencil  works  gritty  and  irregularly.  TAfter 
having  retouched  upon  the  gelatine  film,  the  negative  may  be 
varnished,  and  if,  as  it  occurs  at  times,  certain  parts  have  not  at- 
tained sufficient  opacity,  the  varnished  plate  can  be  retouched 
over  again. 

The  negative  being  placed  on  the  frame,  as  described,  the  light 
should  be  regulated  according  to  its  density — the  greater  the 
density  of.  the  negative  the  stronger  the  light  required — taking 

5 


tare  always  to  use  the  lowest  degree  of  illumination  consistent 
with  the  complete  visibility  of  all  detail  and  half  tone^X  JT  too 
strong  a  light  be  used,  the  retouching  will  show  more  forcibly 
than  appears  in  the  negative,  anjljKmild  ruin_its  delicacy.  The 
aperture  in  the  retouching  easel  should  not  be  too  large,  or  there 
will  be  a  flood  of  light  running  into  the  eyes  that  will  not  only 
dazzle  and  tire  them,  but  render  the  lighter  and  more  delicate 
tones  invisible. 

The  pencil  is  to  be  pointed  in  the  manner  described,  the  final 
"  sharpening  "  being  best  given  by  a  piece  of  emery  paper  or 
cloth  not  too  fine,  a  little  care  being  necessary  to  avoid  breaking 
the  long  and  fine  point.  The  easiest  and  surest  mode  is  to  work 
the  point  by  repeated  strokes  away  from  the  body,  and  not  to 
rub  it  sideways  or  backward  and  forward.  This  hint  will  be 
found  very  useful,  as  the  breaking  of  half  an  inch  of  point  is  very 
irritating. 

First  take  out  of  faces  all  freckles  and  marks,  blotches  of  un- 
equal color,  etc  ,  and  then  very  carefully  make  the  smallest  pos- 
sible amount  of  alteration  in  what  is  usually  termed  the  "  model- 
ing"— that  is,  softening  very  heavy  shadows  and  increasing  the 
prominence  of  some  of  the  leading  lights.  Tfhis  is  done  by  deli- 
cate "dabs"  or  dots,  so  to  speak,  with  the  point  of  the  pencil, 
which  must  be  made  of  the  right  intensity  at  once,  as  the  depth 
cannot  be  increased  by  successive  washes  of  color,  as  in  painting, 
though  if  the  retouching  be  done  in  very  fine  dotting  or  stippling, 
extra  depth  may  be  got  by  carefully  filling  in  between  the  first 
pencilings. 

The  terms  "stippling"  and  "hatching,"  as  they  are  often 
employed,  may  be  briefly  described  as  dotting  and  lining  re- 
spectively. When  there  are  transparent  parts  requiring  a  con- 
siderable amount  of  intensity  given  to  them,  it  will  be  found  next 
to  impossible  to  do  it  at  once,  and  then  the  only  plan  is  to  make 
a  first  retouching  upon  the  unvarnished  negative  as  deep  as  pos- 
sible, varnish,  and  retouch  again.  After  the  spots  are  all  taken 
out  by  stippling,  the  modeling  may  be  done  by  hatching,  mak- 
ing small  lines  only,  as  regular  in  size  and  distance  apart  as  pos- 
sible, and  as  much  as  can  be  done  causing  them  to  follow  the 
lines  or  contours  of  the  features,  or  those  particular  facial  devel- 
opments that  are  being  worked  upon.  It  is  important  that  the 
hatching  should  be  done  in  a  regular  manner,  or  a  very  scratchy 
and  uneven  effect  will  be  produced.  Great  care  must  be  taken 
to  avoid  crossing  the  lines,  or  making  two  strokes  touching  one 
another,  this  being  a  fertile  source  of  "  lumpy"  or  "  scratchy" 
work,  as  it  is  forcibly  called. 

6 


It  will  be  found  of  great  use,  if  not  an  actual  necessity,  to 
have  a  magnifier  for  especially  delicate  work— not  to  be  made 
use  of  from  beginning  to  end,  but  merely  for  particular  portions 
of  the  work,  and  to  aid  a  general  scanning  of  the  whole  when 
completed,  so  as  to  pick  out  any  unevenness  or  roughness.  If 
used  all  through  it  causes  the  work,  strange  as  it  may  appear,  to 
be  less  real  and  flesh-like,  and,  we  may  almost  say,  less  delicate. 
The  glass  should  be  of  good  width,  so  that  both  eyes  can  be 
used,  and  it  is  better  if  it  can  be  affixed  to  a  permanent  support 
which  will  hold  it  at  one  distance  from  the  negative  ;  and  this 
will  materially  lessen  the  fatigue  of  the  eyes  in  using  it. 

The  hatching  may  be  suitably  begun  at  the  forehead  and  fin- 
ished at  the  lower  part  of  the  face,  working  from  the  highest 
lights  so  the  shadows,  and  not  vice  versa.  Every  face  will  impart 
hints  as  to  the  leading  lights  and  shadows  under  varying  modes 
of  illumination. 

We  conclude  by  pointing  out  some  alterations  which  may  he 
made  or  avoided  with  advantage. V"~One  of  the  commonest  faults 
of  a  photograph  is  the  stern  or  "  cross"  expression  so  frequently 
seen,  which  iscaused  by  a  too  strong  light,  or  it  is  the  natural 
expression  of  a  face  at  rest.  One  of  the  chief  seats  of  this  ex- 
pression is  between  the  eyebrows.  It  is  not  caused  by  the  per- 
pendicular line  or  lines,  more  or  less  pronounced,  always  seen 
there  in  persons  somewhat  advanced  in  life,  but  is  produced  by, 
the  contraction  of  the  eyebrow,  which  at  the  end  nearest  the 
nose  will  be  found,  when  under  this  expression,  to  have  taken  an 
angular  form,  and  produced  a  decidedly  darker  shadow  under- 
neath in  the  orbity  If  the  corner  of  this  angle  be  taken  off,  and 
the  heavy,  dark  shadow  be  slightly  lessened,  the  effect  at  times 
is_almost  magical  ;  and  yet  any  one  can  see,  by  looking  at'  a  re- 
touched negative,  that  very  few  retouchers  are  aware  of  this  sim- 
ple expedient,  it  being  generally  thought  that  the  upright  furrows 
cause  the  frown.  --  — 7 

nr^r'  nf  fhp  rhppk  /earest  the  nose/ should  be  most  care- 
ic  :  there  is  often 


fully  and  thoughtfully  done  ;  there  is  otfen  a  delicate  shadow 
which  is  i?iah1p  to  be  taken  out  by  the  unskilled  retoucher  with 
the  effect  of  producing  a  swelled_ch££k.  The  line  often  found 
running  dowrTfrom  the  wings  of  the  nostrils  should  be  carefully 
lightened  withjhe  aid  of  the  knowledge  which  would  be  obtained 
by  a  slight  study  of  the  artist's  own  face  in  a  mirror.  The  differ- 
ence between  a  smile  and  a  sneer  is  caused  by  an  almost  imper- 
ceptible difference  in  the  shading  of  this  furrow  that  cannot  be 
conveyed  in  words, 

T 


Finally,  there  is  the  corner  of  the  mouth,  where  much  may 
often  be  done  if  it  be  borne  in  mind  that  in  a  smile  the  corner  of 
the  lip  is  slightly  turned  up,  and  with  a  serious,  grave  or  crying 
expression  it  takes  an  opposite  direction.  The  hands  may  often 
be  improved  by  taking  out  the  swollen  veins  they  frequently  pre- 
sent in  the  photograph,  though  it  often  happens  that  this  can 
only  be  done  on  each  individual  print. 

In  landscape  negatives,  as  well  as  in  other  negatives,  all  hard 
shadows  should  be  softened,  and  the  lights  strengthened"^but  all 
the  work  should  be  done  on  the  back  of  the  glass/  In  the  foliage 
negatives  taken  with  a  bright  sun,  the  nearest  trees  are  often 
wanting  in  detail,  while  the  more  distant  ones  are  quite  sharp. 
Prints  from  these  negative  have  an  unpleasant  effect,  the  differ- 
ent lines  of  distances  being  too  distinctly  marked  ;  this  may  be 
improved  by  touching  with  a  brush,  not  too  pointed,  and  Indian 
ink  or  blue,  representing  some  leaves  according  to  the  lights 
which  are  already  indicated.  It  is  impossible  to  distinguish  the 
trees  retouched  in  that  way  from  the  others  finely  obtained  on  the 
negative. 

Finally,  if  there  are  any  strong  lights  to  be  put  on  negatives 
for  obtaining  effects  of  snow,  it  is  best  done  on  the  back  of  the 
negative,  either  on  tissue  paper  or  white  varnish. 

The  same  thing  may  be  done  in  negatives  of  clouds  which  are 
sharply  lighted  by  sunlight.  If  the  shadows  are  too  transparent, 
and  the  lights  too  hard,  put  in  some  half  tones,  and  remove  the 
varnish  from  the  lights.  If,  on  the  contrary,  the  light  parts  are 
weak,  strengthen  them  either  with  a  stump  or  brush,  and  remove 
the  varnish  from  the  shadows.  For  positives  and  enlargements 
the  same  work  has  to  be  done,  and  always  in  the  same  way. 

It  will  be  seen,  then,  that  in  the  art  of  retouching  negatives  it  is 
only  in  the  first  step  that  any  difficulty  is  to  be  met  with,  be- 
cause, being  the  most  important,  all  the  rest  follows  from  it,  and 
is,  so  to  speak,  only  the  same  thing  differently  applied.  There- 
fore, with  the  knowledge  of  these  few  various  methods,  and  a 
little  taste  and  use,  one  may  always  be  certain  of  getting  good 
results. 


CHAUTAUQUA  UNIVERSITY. 

LEWIS  MILLER,  PRESIDENT. 
J.  H.  VINCENT,  CHANCELLOR.  R.  S.  HOLMES,  REGISTRAR. 


THE 


j&ljool  of 


SCHOOL    HEADQUARTERS, 

423  BROOME  STREET,  NEW  YORK. 


CHARLES    WAGER     HULL 
Supt.  of  Instruction,  C.  5.  of  P. 


LESSON  XVI I L 

PHOTOGRAPHING     INTERIORS. 

DURING  the  cold  months  of  winter,  when  the  earth  is  covered 
with  snow  and  the  trees  are  devoid  of  their  foliage,  the  landscape 
photographer  finds  fewer  attractive  subjects  for  his  camera  than 
in  the  seasons  when  nature  wears  brighter  garments  and  presents 
more  varied  scenes.  There  are  frost  and  snow  pictures,  to  be 
sure,  and  many  of  exquisite  beauty;  but  they  are  difficult  to  find 
with  the  camera,  and,  when  discovered,  require  a  peculiar  skill 
in  the  photographer  to  be  justly  reproduced  on  his  plate.  At 
this  season  of  the  year,  then,  to  what  shall  we  turn  our  attention  ? 

Portraits  and  in-door  groups,  copying,  and  the  photographing 
of  interiors,  at  once  suggest  themselves  as  suitable  and  pleasant 
work  for  the  winter  months  ;  and  of  all  these,  the  photographing 
of  interiors  can  be  pursued  with  perhaps  the  greatest  real  satis- 
faction and  pleasure. 

Few  are  the  homes  that  have  not,  at  least,  one  room  that  will 
make  an  attractive  photograph  when  properly  lighted  and  ar- 
ranged. Indeed,  the  pleasant  mystery  often  is,  how  so  pretty  a 
photograph  could  be  made  of  "our  very  plain  library."  But  in 
a  photograph  even  an  ordinary  appearing  room  acquires  a  certain 
dignity,  and  we  instinctively  think  of  palace  halls  and  stately 
mansions. 

Especially  attractive  do  one  or  more  rooms  appear  when  seen 
through  doorways  or  arches,  with  portiere  draped  back.  And  then 
there  are  so  many  corners  in  a  house,  mantels  and  fire-places 
that  make  pretty  vignette  photographs.  Not  only  are  such 
photographs  of  the  greatest  interest  to  the  owner  when  made 
in  his  own  home  ;  but  those  of  churches,  theatres  and  famous 
buildings,  and  even  of  private  dwellings,  possess  not  a  little 
architectural  value. 

The  first  requisite  for  making  interiors  is  a  good,  perfectly 
rectilinear,  wide-angle  lens,  and  of  as  short  a  focus  as  will  per- 
fectly cover  the  plate  used.  A  forward-focus  camera  is  very 

2 


convenient  sometimes  in  photographing  interiors,  for  often  it  is 
necessary  to  crowd  well  up  into  a  corner  in  order  to  get  a  good 
field.  Use  always  as  quick  a  plate  as  can  be  obtained,  for  with 
the  room  properly  lighted,  and  using  a  small  diaphragm  so  as  to 
obtain  the  greatest  amount  of  detail  possible,  the  exposure  is  long 
enough,  even  with  the  quickest  plate,  to  satisfy  the  most  obstinate 
advocate  of  slow  emulsions. 

The  lighting  is,  perhaps,  the  cause  of  most  failures.  No  direct 
sunlight  must  be  admitted,  but  as  much  diffused  light  as  possible, 
and  the  more  the  better.  If  possible,  light  the  interior  from  the 
rear  and  sides;  but  if  it  is  impossible  to  avoid  a  window  in  front 
of  the  lens,  it  must  be  carefully  closed  with  its  shutters  and  a 
curtain  drawn  over  them.  If  this  precaution  is  not  taken, 
"halation"  is  sure  to  follow — "that  appearance  of  halo — dark  in 
the  negative,  light  in  the  print — which  makes  its  appearance 
round  very  bright  objects  in  photographs,"  which  Burton  de- 
scribes. When  the  sun  shines  directly  through  the  rear  or  side 
windows,  its  light  can  be  diffused  by  drawing  the  shades  over  the 
windows,  if  they  be  white  ;  if  not,  white  sheeting  or  even  paper 
answers  well.  But  an  overcast  day,  if  it  be  not  too  dark,  is  the 
best  for  photographing  interiors. 

Halation  is  also  caused  by  light  which  is  reflected  from  the 
back  of  the  plate.  The  greater  part  of  the  transmitted  light 
strikes  the  back  of  the  plate.  That  travelling  in  a  direction  at 
right  angles  to  or  forming  a  large  angle  with  the  back  of  the 
glass,  is  transmitted  through  it ;  but  those  rays  which  strike  the 
back  of  the  glass  at  the  angle  of  total  reflection  are  sent  back  to 
the  front  surface,  where  they  pass  into  the  emulsion. 

The  means  of  avoiding  the  objectional  appearance  caused  in 
this  w^y  is,  of  course,  to  back  the  plate  with  some  substance 
which  absorbs  light.  Bitumen  answers  well  for  this  purpose, 
also  black  carbon  tissues  moistened  with  glycerine.  Plain  paper 
of  a  dead  black  surface,  cut  into  the  proper  size,  does  very  well 
and  is  easy  to  obtain  and  adjust. 

By  the  use  of  paper  films,  instead  of  glass  plates  for  making  in- 
teriors, one  cause  of  halation  is  largely  removed  ;  but  even  with 
them  an  even  and  harmonious  light  is  absolutely  necessary  in  or- 
der to  be  perfectly  free  from  this  annoyance. 

Do  not  strive  after  effects  of  chiaro-oscuro.  We  must  depend 
on  our  arrangement  and  the  development  of  the  negative  alone 

3 


for  artistic  effect  in  the  work.  With  a  soft,  even  light  over  the 
entire  room  the  best  and  only  successful  interiors  can  be  made. 

The  exposure  must  be  ample.  An  over-exposed  plate  on  an 
interior  can  be  treated  with  far  greater  chances  for  success  than 
one  which  has  been  under-timed  ;  indeed,  an  under-exposed 
negative  had  best  be  thrown  into  the  waste  pile,  and  the  devel- 
oper, time  and  patience  of  the  operator  saved  for  less  hopeless 
attempts.  No  definite  time  can  be  given  as  the  correct  one  for 
an  exposure  on  an  interior,  for  so  much  depends  on  the  amount 
and  degree  of  light,  which  is  ever  changing.  By  experience  one 
acquires  the  judgment  which  is  necessary  to  decide  the  proper 
length  of  exposure,  and  the  illumination  on  the  ground  glass 
soon  becomes  a  sure  sign  to  the  practiced  eye. 

Development,  fixing  and  washing  is  proceeded  with  in  the 
usual  manner,  and,  if  the  exposure  be  correct,  will  be  found  to 
present  no  new  difficulties.  In  this,  as  in  everything  else,  "  prac- 
tice makes  perfect,"  and  by  practice  alone  can  we  hope  to  attain 
perfection. 


CHAUTAUQUA  UNIVERSITY. 

LEWIS  MILLER,  PRESIDENT. 
J.  H.  VINCENT,  CHANC&LLOR.  R.  S.  HOLMES,  REGISTRAR. 


THE 


(Sjautouqua  {Scjjool  of  PhofopphJ, 

SCHOOL    HEADQUARTERS, 

423  BROOME  STREET,  NEW  YORK. 


CHARLES    WAGER     HULL, 
Supt.  of  Instruction,  C.  S.  oj  P. 


LESSON   XK, 


Reproductions    and    Photographing 
Inanimate  Objects. 

PHOTOGRAPHERS  are  almost  daily  called  upon  to  copy  not  only 
photographs,  but  also  paintings  in  oil  or  water  colors,  engravings, 
and  the  like.  The  mode  of  operating  does  not  differ  much  from 
that  heretofore  described,  but  several  important  points  must  be 
observed^  to  which  our  attention  has  not  yet  been  directed,  and 
without  which,  this  work  will  give  but  little  satisfaction. 

Reproductions  are  made  either  in  the  natural  size  of  the 
original,  enlarged  or  reduced.  In  any  case  the  proportions  of  the 
original  must  be  preserved.  To  do  this  the  apparatus  must  be 
placed  directly  opposite  the  object  to  be  photographed,  and  in 
right  angles  to  it.  Obliquity  between  them  results  in  incorrect 
results,  no  matter  how  superior  the  lens  may  be.  The  object  to 
be  copied  should  receive  a  direct  front  light.  If  the  work  is  to 
be  done  under  the  skylight,  camera  and  object  may  be  placed 
upon  an  elongated  platform,  movable  upon  a  pivot  with  ball  and 
socket  arrangement,  so  as  to  place  the  original  in  a  position 
oblique  to  the  floor,  but  parallel  with  the  skylight.  If  the  object 
be  very  large,  side  screens  may  be  required  to  reflect  light,  or  to 
subdue  it  before  a  uniform  illumination  can  be  attained. 

We  have  seen  in  practice  that  the  farther  away  the  object  is 
from  the  camera  the  smaller  the  picture  will  be,  and  by  reversing 
the  axiom  we  will  find  that  a  very  much  enlarged  picture  can  be 
made  only  by  bringing  the  camera  quite  close  to  the  object  to  be 

2 


copied.  The  lesson.  "  Printing  on  Bromide  Paper,"  speaks  of" 
enlargements  ;  the  principles  laid  down  there  may  be  adhered  to 
in  all  other  modes  of  enlarging.  For  portraits,  when  the  central 
part  of  the  picture,  the  head,  is  the  main  object,  an  ordinary  por- 
trait lens  may  be  used  ;  while  landscapes,  architectural  views, 
drawings,  or  engravings,  of  which  equal  sharpness  all  over  the 
picture  is  demanded,  rectilinear  lenses  must  be  used  like  the 
Morrison  copying  lenses,  the  Wale  "  Universal,"  the  Gundlach 
rectigraph,  or  the  Steinheil  aplanat. 

A  new  apparatus,  the  Scovill  Enlarging,  Reducing,  and  Copying 
Camera,  is  well  adapted  for  the  work.  Its  form  of  construction 
is  made  apparent  by  the  illustration  here  given  : 


It  is  principally  intended  for  the  copying  of  negatives  or  glass 
positives,  but  by  removing  the  kits  in  the  front,  the  lens  can  be 
inserted  into  the  same  opening,  rendering  the  apparatus  capable 
of  copying  other  objects  as  well.  To  copy  a  negative  in  the 
natural  size,  place  it  in  the  kit  on  the  front  of  camera  and  button 
it  in.  Attached  to  the  centre  frame  of  the  camera  is  a  division 
upon  which,  on  the  side  towards  the  camera  front,  a  lens  is 
mounted.  Suppose  this  to  be  a  quarter-plate  portrait  lens,  the 
focal  length  of  which  we  will  suppose  to  be  four  inches  :  draw 
back  the  centre  frame  and  the  lens  to  twice  the  focal  length 
of  the  lens,  slide  the  back  frame  with  ground  glass  the  same  dis- 
tance from  the  centre  frame.  To  enlarge  with  the  same  lens  to 
eight  times  the  size  of  the  original,  the  centre  of  the  lens  must 
be  four  and  one-half  inches  from  the  negative,  and  the  ground 
glass  be  thirty-six  inches  from  the  centre  of  the  lens.  To  reduce 
in  the  same  proportion,  reverse  and  have  thirty-six  inches  from 
the. centre  of  the  negative,  and  from  centre  of  lens  to  ground 


glass  four  and  one-half  inches.     These  examples  will  furnish  a 
key  to  the  following  table  : 


TABLE  FOR   ENLARGEMENTS. 

Copied  from  the  "British  Journal  Almanac  for  1882." 


Focus  OF  LENS. 

TIMES  OF  ENLARGEMENT  AND  REDUCTION. 

In. 
2 

1 
In. 
4 
4 

2 
In. 
6 
3 

3 
In. 

8 
2% 

4 
In. 
10 

2^ 

5 
In. 
18 
2f 

6 
In. 
14 
2i 

7           8 
In.        In. 
16         18 
2f         2i 

2^ 

5 
5 

^ 

10 

H 

12}£ 
3^ 

15 
3 

% 

20         22^ 

2|         2|| 

3 

6 
6 

9 
VA. 

12 

4 

15 
3% 

18 
3* 

21 
3i 

24         27 
8f         8f 

3^ 

7 
7 

10& 

s3 

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10^       lOf       10i 

It  is  assumed  that  the  photographer  knows  exactly  what  the 
focus  of  his  lens  is,  and  that  he  is  able  to  measure  accurately 
from  its  optical  centre.  The  use  of  the  table  will  be  seen  from 
the  following  illustration  : — A  photographer  has  a  carte  to  enlarge 
to  four  times  its  size,  and  the  lens  he  intends  employing  is  one  of 
six  inches  equivalent  focus.  He  must,  therefore,  look  for  4  on 
the  upper  horizontal  line,  and  for  6  in  the  first  vertical  column, 
and  carry  his  eye  to  where  these  two  join,  which  will  be  at 


30— 7^-.  The  greater  of  these  is  the  distance  the  sensitive  plate 
must  be  from  the  centre  of  the  lens  and  the  lesser,  the  distance 
of  the  picture  to  be  copied.  To  reduce  a  picture  any  given 
number  of  times  the  same  method  must  be  followed,  but  in  this 
case  the  greater  number  will  represent  the  distance  between  the 
lens  and  the  picture  to  be  copied  ;  the  latter,  that  between  the 
lens  and  the  sensitive  plate.  This  explanation  will  be  sufficient 
for  every  case  of  enlargement  or  reduction. 

If  the  focus  of  the  lens  be  twelve  inches,  as  this  number  is  not 
in  the  column  of  focal  lengths,  look  out  for  6  in  this  column  and 
multiply  by  2  ;  and  so  on  with  any  other  numbers. 

Reproductions  require  proportionally  much  longer  time  of  ex- 
posure than  portraits  or  landscapes,  and  in  this  particular  point 
frequent  errors  are  made,  generally  towards  over-exposures. 
The  operator  must  learn  by  practice  how  much  time  to  give, 
probably  with  the  loss  of  a  few  plates,  before  the  required  ex- 
perience can  be  attained. 

As  with  the  full  aperture  of  the  lens,  enlarged  pictures  will  ap- 
pear upon  the  ground  glass  with  a  want  of  definition,  small  stops 
become  necessary  to  retain  the  original  sharpness. 

Oil  paintings  demand  almost  invariably  a  direct  front  illumina- 
tion. If  from  the  glossy  varnish  reflections  occur,  they  must  be 
counteracted  by  a  dark  side  screen  ;  naturally  with  loss  of  much 
light.  Aquarelles  or  pastelles  appearing  brighter  are  easier  to 
copy.* 

Daguerreotypes  or  pictures  under  glass  must,  on  account  of 
their  reflective  properties,  be  placed  so  that  reflections  of  light 
are  overcome.  Daguerreotypes  often  show  buff  marks  from  pol- 
ishing the  metallic  plate.  It  is  better  to  copy  them  by  direct  or 
reflected  sunlight.  Photographs  when  highly  burnished  or  en- 
ameled receive  the  same  treatment  as  other  pictures  with  glossy 
surfaces.  Ordinary  photographs  generally  copy  very  well,  with 
the  exception,  perhaps,  of  those  very  much  enlarged,  when  the 
grain  of  the  paper  shows  rather  too  strongly. 

Plates  may  be  developed  as  described  in  Lesson  No.  VI.,  or 
with  any  other  of  the  standard  formulae  for  developers. 

For  line  work,  when  a  negative  in  black  and  white  only  is  de- 
sirable, and  when  no  half  tones  or  modulations  are  to  be  pre- 
served, we  resort  to  the  ferrous  oxalate  described  in  the  Lesson 
on  "  Printing  on  Permanent  Bromide  Paper."  For  that  class  of 

*  The  copying  of  paintings  will  receive  more  detailed  consideration  in  the  Lesson  on 
"  Orthochromatic  Methods. 


work,  time  of  exposure  is  even  more  important  than  with  ordinary 
copying,  as  by  a  probable  reinforcing,  or  long  continued  develop- 
ing, the  sharpness  of  lines  is  often  considerably  damaged,  making 
the  negative  utterly  worthless  if  a  relief  plate  is  to  be  made  from 
it.  Referring  to  the  formula  described  before,  we  take  three 
ounces  of  the  solution  of  oxalate  of  potash  and  add  to  it  one 
ounce  of  the  solution  of  sulphate  of  iron.  If  more  iron  is  used, 
the  mixed  solution  will  turn  turbid  and  separate  a  yellow  precipi- 
tate ;  in  such  state  it  should  not  be  used.  The  perfectly  clear 
and  transparent  red  solution  is  poured  over  the  plate,  and  the 
appearance  of  the  image  closely  watched.  If  the  image  comes 
with  anything  like  rapidity,  pour  the  developer  off,  wash  slightly, 
and  flood  the  plate  with  a  solution  of  pure  oxalate  for  a  minute 
or  two,  pour  off,  and  without  washing  continue  with  the  original 
developer.  If  the  effects  of  over-exposure  are  still  apparent,  re- 
strain with 

Iodine 15      grains, 

Alcohol 31^  ounces, 

to  which,  after  being  dissolved,  three  and  a  quarter  ounces  of 
water  are  added. 

From  fifteen  to  twenty  drops  of  this  compound  added  to  the 
developer  will  secure  the  intensity  and  clearness  of  the  lines  de- 
sirable in  black  and  white  negatives. 

Whenever  legal  documents,  autographs,  commercial  papers, 
etc.,  are  to  be  reproduced,  the  above  method  will  prove  to  be 
perfectly  reliable. 

Photographing  Inanimate  Objects. 

A  variety  of  mercantile  articles,  machinery,  inventor's  models, 
etc.,  are  often  brought  before  the  photographer.  A  few  hints  re- 
garding the  treatment  of  objects  more  frequently  occurring  will 
also  be  mentioned  in  this  Lesson. 

Fabrics,  Paper  Hangings,  Embroideries,  etc. — If  it  is  the  object 
to  photograph  them  for  commercial  purposes,  they  should  be 
stretched  upon  a  plain  board  or  screen,  in  order  to  present  a 
plane  surface.  The  nature  of  their  colors  invariably  demands 
orthochromatic  plates. 

Laces  should  be  placed  similarly,  but  in  order  to  show  the  deli- 
cacy of  the  structure  quite  well,  they  should  be  placed  upon  a 
ground  of  well  contrasting  color.  White  upon  black,  or  vice 
versa. 

6 


Glassware.— Ornamented  or  cut  plates  are  copied  against  a 
dark  ground,  to  make  the  transparent  parts  appear  black  upon 
the  photograph. 

Hollow  Glassware,  Cut  or  Engraved,  may  be  either  filled  with 
a  colored  opaque  liquid,  or  as  in  the  case  of  globes  or  lamp-shades, 
be  lined  with  dark  muslin.  They  should  receive  such  an  illumina- 
tion as  to  produce  distinct  lights  and  shadows,  without  which 
the  photograph  will  not  be  plastic. 

Porcelain  or  Delft  should  be  similarly  lighted.  The  objects 
being  generally  white  and  glossy,  a  proper  exposure  is  important 
to  obtain  brilliant  lights  and  fine  shadows. 

Bronzes. — On  account  of  their  non-actinic  color  and  high  gloss, 
lighting  requires  a  good  judgment.  To  obtain  a  good  general 
effect,  a  slight  over-exposure  is  not  only  admissible  but  some- 
times necessary. 

Silver  or  Plated-ware. — Owing  to  their  high  polish  these  arti- 
cles can  be  photographed  only  in  very  subdued  light.  To  avoid 
inartistic  reflections,  skylight  or  windows  should  be  covered  with 
a  thin  white  fabric  or  white  tissue  paper,  and  side  screens  be 
used  to  subdue  or  control  light.  *In  order  to  do  away  with  the 
reflected  image  of  camera  and  operator,  often  quite  visible  upon 
larger  objects,  a  screen  of  neutral  color  should  be  placed  imme- 
diately in  front  of  the  camera,  allowing  merely  an  aperture  for 
the  lens. 

Machinerv,  when  taken  out  of  doors,  is  quite  easy  to  manage, 
but  much  trouble  occurs  when  the  object  is  to  be  photographed 
in  the  shop,  store  or  warehouse,  whose  light  is  generally  poor, 
and  the  distance  from  the  position  the  camera  can  occupy  but 
insufficient.  All  available  light  should  then  be  admitted,  and  as 
heavy  machinery  cannot  be  moved  at  the  will  of  the  operator,  he 
should  be  provided  with  several  lenses  of  different  focal  length. 

Models. — The  inventor  directs  from  what  point  they  are  to  be 
taken,  and  he  knows  exactly  what  he  wants  to  show  in  the  pho- 
tograph. The  United  States  Patent  Office  prescribes  a  particular 
size,  7x11  inches,  with  sufficient  margin.  Only  this  size  is  ac- 
ceptable. 

Plaster  of  Paris  Cornices,  Centre  Pieces,  Brackets,  etc.,  must  be 
fastened  to  a  white  ground,  and  be  placed  in  a  light  falling  ob- 
liquely upon  them,  to  secure  distinct  and  transparent  shadows 
and  brilliant  high  lights. 

Marble  Statuary  and  Similar  Works  of  Sculpture  require  illum- 
ination very  much  as  portraits  do,  allowing,  however,  for  their 


white  color.  The  technical  part  offers  no  difficulties,  but  it  is 
highly  important  to  preserve  a  good  balance  between  lights  and 
shadows. 

Furniture  and  Cabinet  Articles. — The  photographer  is  always 
inclined  to  place  them  in  a  perspective  position,  never  quite 
suitable  to  the  manufacturer,  whose  demands  should  be  re- 
spected at  least  in  this  respect.  The  difficulty  occurring  here  is 
to  make  the  quality  of  the  wood  show  distinctly  as  well  as  the 
upholstery  and  form. 

Flowers  and  Leaves,  when  nicely  arranged,  make  very  interest- 
ing and  beautiful  photographs.  As  a  correct  representation  of 
color  values  is  one  of  the  first  conditions,  we  invariably  photo- 
graph them  upon  orthochromatic  plates. 

All  these  and  kindred  objects  must  be  perfectly  sharp  ;  very 
small  stops  must  therefore  be  employed  when  photographing 
them.  Besides,  they  must  be  correctly  exposed  and  carefully 
developed,  for  they  are  satisfactory  only  when  free  from  blemishes. 


CHAUTAUQUA  UNIVERSITY, 

LEWIS  MILLER,  PRESIDENT. 
J.  H.  VINCENT,  CHANCELLOR.  R.  S.  HOLMES,  REGISTRAR. 


THE 


Cij&utauqua  j&jool 


SCHOOL    HEADQUARTERS, 

423  BROOME  STREET,  NEW  YORK. 


CHARLES    WAGER     HULL 
Supt.  of  Instruction,  C.  S.  oj  P. 


LESSON  XX. 

Orthochromatic  or  Color-Sensitive  Photog- 
raphy. 

WHEN  we  subject  photographs  to  critical  examination,  and 
compare  the  effects  which  colors  have  produced  upon  our  plate, 
with  their  appearance  of  brightness  or  value  of  tone  in  the 
original,  we  find  that  our  reproduction  is  very  far  from  a  correct 
representation  of  what  the  eye  has  seen.  While  form,  light  and 
shade  have  photographed  in  perfect  correspondence  with  the 
original,  colors  have  not  been  so  reproduced.  Our  plates  copy 
the  bright  yellowish  green  of  vernal  foliage  quite  dark,  and  the 
far-distant  blue  mountains  in  a  landscape  so  extremely  light,  that 
most  careful  development  is  not  capable  of  rendering  them 
with  justice  to  the  general  aspect.  The  bright  scarlet  flower  of 
the  geranium  copies  alike  with  the  green  leaves  of  the  plant,  the 
crimson  tulips,  seamed  with  yellow,  shows  no  color  contrast,  and 
the  dark  blue  hyacinth  appears  nearly  white  in  the  ordinary  pho- 
tograph. 

The  cause  of  this  paradox  in  photography  was  well  understood 
by  the  earliest  experimenters,  they  knowing  very  well  why  differ 
ent  effects  could  not  be  expected. 

All  light  does  not  act  upon  a  photographic  surface,  but  only 
certain  parts  of  it  do,  while  others  remain  inactive. 

The  force  or  power  that  causes  photographic,  or  photo-chemi- 
cal action,  scientists  have  called  actinism,  and  the  active  rays 
actinic. 

Actinic  rays  are  those  found  on  one  end  of  the  spectrum,  the 
violet  and  blue,  called  most  refrangible  by  spectrum  analysts.  Red, 
orange  and  yellow,  at  the  other  end  of  the  spectrum,  do  not  act 
at  all,  or  but  very  little.  These  rays  do  not  deviate  so  much  from 
the  path  of  undivided  light,  like  blue  and  violet  do,  and  are,  there- 
fore, called  less  refrangible. 

3 


If  we  expose  an  ordinary  photographic  plate  at  the  solar  spec- 
trum, these  effects  will  show  to  perfection  how  differently  the  two 
ends  of  the  spectrum  work.  Violet  and  blue  will  give  very  pro- 
nounced impressions,  but  they  will  diminish  more  and  more  until 
at  the  other  end,  no  effect  is  visible. 

This  is  exactly  what  we  notice  in  every-day  photographs.  Yel- 
low and  orange  copy  much  too  dark,  some  reds  do  not  impress 
the  plate  at  all  ;  and  blue  and  violet,  no  matter  how  dark  they  may- 
be, come  invariably  too  light ;  and  the  variety  of  colors  in  fabrics, 
embroideries,  paintings,  and  many  natural  objects  have  thus  given 
endless  dissatisfaction  to  the  photographer. 

For  many  years  it  was  considered  as  impossible  to  remedy  these 
defects,  as  we  now  think  it  to  be  out  of  the  question  to  photograph 
colors  themselves. 

With  orthochromatic  or  color-sensitive  plates  we  overcome  these 
anomalies,  and  produce  effects  nearly  correct  in  their  value  of 
brightness. 

An  immense  amount  of  practical  work  and  labor  had  to  be  done, 
before  anything  worthy  of  interest  was  attained,  but  we  cannot 
deny  that  the  discovery  of  the  process  is  based  absolutely  upon 
theories,  and  has  been  established  by  experiments  in  spectroscopy. 
These  experiments  were  based  again  upon  one  principle,  that  is, 
the  addition  of  some  substances,  possessing  the  power  of  absorb- 
ing, and  converting  into  chemical  energy  those  rays  which  upon 
an  ordinary  plate  have  no  effect. 

For  this  purpose,  a  large  number  of  dye-stuffs  were  found  to  be 
most  effective.  They  are  themselves  sensitive  to  light,  for  they 
bleach  when  exposed  to  it.  Bleaching  action  was  found  to  be 
strongest  on  the  red  end  of  the  spectrum,  which  has  no  effect  on 
ordinary  plates.  The  most  generally  adopted  theory  on  this  occa- 
sion is,  that  the  energy  absorbed  in  bleaching  the  dye,  is  trans- 
mitted to  the  silver  haloid  of  the  plate,  upsetting  its  equilibrium, 
and  rendering  it  capable  of  development. 

Of  the  many  dyes  that  have  been  experimented  with,  only  a 
few  have  been  retained  for  their  excellent  activity,  although 
many  more  are  being  added,  according  to  the  researches  con- 
stantly made.  It  is  true,  not  all  of  these  colors  sensitize  alike,  or 
for  several  colors  at  the  same  time,  and  as  the  spectrum  photog- 
rapher proposes  to  examine  distinct  spectrum-regions  with  dis- 
tinct media,  so  does  the  practical  photographer  select  colors  that 
give  the  best  general  effect. 

Some  colors,  known  by  the  name  of  cosines,  answer  admirably, 
but  many  of  them  do  not,  and  all  of  them  refuse  to  reproduce  red, 

4 


beyond  a  certain  point.  A  very  happy  combination  of  colors, 
belonging  to  another  class,  has  been  made,  which  show  sensitive- 
ness far  into  the  regions  of  the  spectrum  red,  by  which  pigment 
colors  are  rendered  exceedingly  well.  This  action  is  due  to  one 
of  its  ingredients,  cyanine,  or  chinoline  blue,  the  most  red  sensi- 
tive substance  known. 

To  obtain  the  best  general  effects  in  pigment  colors,  we  em- 
ploy another  color,  the  erythrosine,  also  an  cosine,  or  belonging 
to  that  group,  With  it  the  most  practical  results  can  be  obtained, 
for  it  sensitizes  to  perfection  up  to  orange,  yellow  and  green, 
giving  at  times  quite  correct  reproductions  of  red,  when  not  per- 
fectly pure  and  partly  mixed  with  other  colors.  And  we  find  but 
rarely  pure  red  in  pictures,  fabrics  or  embroideries,  hence  ery- 
throsine has  been  selected  pre-eminently  as  a  sensitizer  for  com- 
mercial plates,  or  every-day  work. 

Occasionally,  cyanine,  in  small  portions,  is  added  to  the  ery- 
throsine to  obtain  better  red-sensitiveness,  and  it  acts  then  very 
satisfactory  in  that  combination. 

Violets  and  blues  will,  even  with  those  plates,  exercise  a  very 
violent  action,  and,  to  suppress  it,  a  ray  filter,  principally  of  a 
pure  yellow  color,  is  employed,  it  being  placed  between  the  ob- 
jective and  sensitive  plate. 

At  first,  the  color  itself  was  incorporated  with  the  emulsion, 
and  with  that  the  plates  were  coated.  Practical  work,  and  Mr. 
Pleuer,  with  his  centrifugal  machine,  showed  how  that  but  an  ex- 
tremely small  quantity  of  color  was  requisite  to  give  effects.  In 
fact,  after  an  emulsion  had  been  colored,  he  separated  from  it 
the  bromide  of  silver,  re-emulsified  it,  and,  with  the  infinitessimal 
amount  of  color  combined  with  the  silver,  obtained  the  same 
effects.  All  this  led  to  the  redemption  of  an  almost-forgotten 
process,  the  staining  of  ready-coated  plates  to  color-sensitize 
them. 

This  way  of  working  has  become  more  popular  than  any  other 
method,  and  although  color-sensitive  plates,  colored  in  the  emul- 
sion, have  become  an  article  of  commerce,  stained,  or  bath- 
plates,  as  they  are  commonly  termed,  seem  to  be  preferred  by 
most  operators. 

For  general  work  erythrosine  has  been  found  to  be  the  most 
effective,  and  a  preparation  known  as  the  S.  P.  C.  Flandrau 
Orthochromatic  Solution  carries  it  as  chief  ingredient. 

With  this  solution  any  photographer  may  make  his  own  ortho- 
chromatic  plates,  and  any  good  plate  may  be  successfully  ren- 
dered orthochromatic,  by  simply  bathing  it  with  the  erythrosine. 

5 


When  orthochromatic  plates  are  used  for  reproductions  or 
landscape  work,  it  is  advisable  to  color  sens.tize  plates  of  only 
moderate  rapidity.  The  Carbutt  ''  B"  and  the  Cramer,  of  lower 
grade,  answer  very  well  for  this  purpose,  while  for  shorter  ex- 
posures the  Eastman  Special  is  very  well  adapted. 
The  formulas  are  as  follows  : 

PRELIMINARY  BATH. 

Aqua  ammonia 1  dram. 

Water 7  ounces. 

COLOR  BATH. 

Erythrosine 1^  drams. 

Aqua  ammonia 2      drams. 

Water  (distilled) 5}^  ounces, 

and  the  directions  are  simple. 

Immerse  a  plate  of  medium  sensitiveness  in  the  preliminary 
bath  and  allow  it  to  remain  therein  for  three  minutes.  After  re- 
moval, drain  well,  and  without  washing,  plunge  the  plate  in  the 
coloring  bath,  rocking  it  gently  to  secure  uniform  contact  with 
the  solution.  The  plate  should  not  remain  in  the  color  bath 
longer  than  seventy-five  seconds,  as  a  long-continued  exposure 
to  the  color  solution  will  depress  the  general  sensitiveness,  with- 
out increasing  that  for  colors.  If  a  large  number  of  plates  are 
prepared  with  the  same  solution  it  is  advisable  to  add,  after  the 
eighth  or  tenth  plate,  about  ten  or  twenty  drops  of  erythrosine. 
The  colored  plates  must  be  well  drained,  reared  upon  blotting 
paper,  and  dried  in  the  ordinary  closet. 

Colored  plates  may  be  exposed  while  still  wet,  and  the  general 
sensitiveness  is  somewhat  decreased  thereby.  If,  however,  the 
object  to  be  photographed  requires  a  very  long  exposure,  it  is 
better  to  use  a  dried  plate. 

Developing  erythrosine  plates  offers  no  serious  difficulties,  but 
it  must  be  remembered  that  the  plates  being  so  sensitive  to  color 
especially  yellow,  the  process  must  be  carried  on  either  in  the 
shadow  of  a  subdued  ruby  lantern,  or  a  light  obscured  by  several 
thicknesses  of  brown  tissue  paper. 

To  suppress  the  violent  action  of  blue  and  violet,  a  yellow 
screen  is  placed  between  the  sensitive  surface  and  the  objective  ; 
the  best  method  being  to  fasten  the  screen  on  the  back  of  the 
front  bearing  the  lens.  It  being  difficult  to  obtain  glass  of  pure 
yellow  color,  photographers  prepare  these  screens  themselves,  by 
coating  a  very  thin  and  white  plane  parallel  glass,  with  xanthine 
collodion,  in  a  similar  manner  as  we  have  learned  to  varnish  our 
n°gatives. 


The  yellow  color  imparted  to  the  collodion  is  sensitive  to  light, 
and  plates  prepared  with  it,  will  fade  when  exposed  unnecessarily. 

With  the  interposition  of  the  yellow  screen,  which  is  absolutely 
necessary  for  the  copying  of  objects  in  which  blue  and  violet  pre- 
dominates, the  time  of  exposure  must  be  increased  from  three  to 
six  times  that  of  an  ordinary  plate. 

With  artificial  light  of  sufficient  force  the  yellow  screen  can  be 
dispensed  with,  a  yellow  cylinder  globe  or  shade  placed  over  the 
source  of  light  answering  equally  well. 

The  yellow  glass  should  be  very  thin  ;  if  unnecessarily  thick 
the  time  of  exposure  becomes  longer.  Focus  should  be  taken 
with  it,  as  a  refraction  of  light  may  occur,  making  a  perceptible 
difference. 

The  reproduction  of  oil  paintings,  aquarells,  fabrics,  and  other 
articles,  colored  highly  in  various  shades  does  not  require  any  par- 
ticular precautions.  When  much  red  is  present,  the  exposure 
should  be  lengthened  ;  with  the  absence  of  blue  the  yellow  screen 
may  be  dispensed  with,  neither  is  it  required  for  general  land- 
scape work. 

Artificial  light,  rich  on  yellow  and  orange  light,  allows  work 
without  the  screen. 

The  developing  process  must  be  carried  on  in  weaker  light  than 
generally  is^  used.  As  a  formula  giving  very  good  results  we  may 
adopt : 

1.— Granulated  sulphite  of  soda 3  ounces. 

Water 1  quart. 

In  this  solution  dissolve  : 

2.— Pyrogallic  acid >£  ounce. 

Granulated  carb.  of  soda 2  ounces. 

Water 1  quart. 

For  normal  exposure  add  I  ounce  of  water  to  1  ounce  of  each  of 
No.  1  and  No.  2. 

All  orthochromatic  plates  should  receive  a  full  exposure,  if  too 
much  time  has  been  given,  restrain  with  bromide  of  potassium, 
not  with  bromide  of  ammonium. 

Development  had  better  be  commenced  in  total  darkness.  Af- 
ter the  expiration  of  two  minutes,  when  the  color-stuff  has  been 
partly  washed  away  the  plate  may  be  examined  in  a  weak  red  light, 
and  the  process  may  therein  be  continued.  Fixing,  washing,  in- 
tensifying or  reducing  is  accomplished  in  the  same  way  as  with 
ordinary  plates.  With  some  emulsions  the  color  is  difficult  to 
wash  off  the  plate  ;  when  this  is  the  case  a  little  alcohol  will  re- 
move it  more  effectually  than  water. 

7 


, 


CHAUTAUQUA  UNIVERSITY. 

LEWIS  MILLER.  PRESIDENT. 
J.  H.  VINCENT,  CHANCELLOR.  R.  S.  HOLMES,  REGISTRAR. 


THE 


ftjautsauqua  $cljool  of  Photograph), 

SCHOOL    HEADQUARTERS, 

423  BROOME  STREET,  NEW  YORK. 


CHARLES     WAGER     HULL.. 
Supt.  of  Instruction,  C.  S.  of  P. 


LESSON  XXI. 


Transparencies  and  How  to   Make  Them. 

THERE  are  various  methods  and  processes  for  making  trans- 
parencies, many  of  which  have  passed  into  history,  and,  as  the 
object  of  this  lesson  is  to  place  before  the  reader  the  latest 
method,  combining  simplicity  of  manipulation  with  perfection  of 
result,  it  will  be  only  necessary  to  enumerate  the  various  methods 
of  the  past,  without  entering  into  a  detailed  description  of  them. 
They  comprise  the  albumen,  collodio-albumen,  collodio-bromide, 
bath  dry  plate,  in  which  a  bromoiodised  collodion  plate  is  sensi- 
tized in  a  solution  of  silver  nitrate,  and,  after  washed  and  coated 
with  a  preservative,  collodio-chloride,  wet  collodion  process, 
which  is  still  used  by  professional  slide  makers,  carbon  process 
and  VVoodbury  process. 

At  the  present  time  two  processes  are  in  use  only  in  America, 
viz.,  the  old  wet  collodion  process,  and  the  new  gelatine  dry 
plates,  the  first  limited  in  use  by  those  making  lantern  slides 
mainly  for  advertising  purposes,  while  the  new  gelatine  dry  plate, 
of  the  special  kind  made  for  producing  transparencies,  known  as 
Carbutt's  Gelatino-Albumen  Plate,  is  universally  used  by  ama- 
teurs and  the  professional  portrait  and  landscape  photographer  ; 
and  it  is  in  the  use  of  these  plates  we  now  proceed  to  describe 
how  to  produce  from  your  negatives  what  is  conceded  the  finest 
positive  obtainable. 

The  requisites  for  contact  printing  are  a  deep  printing  frame, 
a  size  larger  than  the  negative  to  be  used,  with  a  flat  glass  bottom 
free  from  scratches;  crystal  plate  is  best;  some  thin  red  enameled 
label  paper  for  masks,  a  Carbutt  Multum  in  Parvo  Lantern,  or 
other  artificial  light,  and  transparency  plates  of  suitable  size  ; 
those  for  lantern  slides  are  made  on  thin  crystal  glass  of  the  now 
accepted  standard  size,  3^x4  inches;  for  the  larger  size  trans- 
parencies they  are  now  made  on  fine-ground  glass,  which  has 
the  advantage  over  the  clear  glass.  That  the  image  is  rendered 
in  its  right  position,  when  made  by  contact  with  the  negative, 
just  as  a  silver  print  would  be,  the  obscured  side  of  the  glass 

2 


being  back  of  the  image,  it  only  remains  to  cover  it  with  a  clear 
cover  glass  and  mount  in  a  suitable  sized  metal  frame  sold  for 
that  purpose.  The  transparency  need  not  be  confined  to  the  size 
of  the  negative  ;  the  image  can  be  enlarged  or  reduced  to  suit 
taste  and  circumstances  ;  nor  is  it  absolutely  necessary,  for  the 
purpose  of  enlarging  or  reducing  the  image,  that  a  camera  for 
that  purpose  be  provided,  if  the  use  of  a  small  room  can  be  com- 
manded, and  the  light  shut  out  all  but  one  light  in  the  lower  sash; 
over  this  light  must  be  placed,  and  covering  the  entire  surface, 
a  light  of  fine  ground  glass  which  will  give  an  even  defused  light, 
passing  through  the  negative  ;  beneath  this  a  support  for  the 
negative  should  be  placed.  The  same  camera  and  lens,  used  in 
making  the  negative,  can  be  used  for  making  the  transparenc) — 
providing  the  image  is  to  be  reduced  in  size,  and  the  negative  can 
be  held  upright  in  one  of  the  plate-holders,  removing  the  septum 
and  dark-slides,  and  placing  the  holder  with  the  negative  on  the 
support  before  the  light  passing  through  the  ground  glass.  The 
camera  itself  may  be  supported  on  a  board,  raised  to  such  a 
height  that  the  lens  will  centre  with  the  centre  of  the  negative, 
care  being  taken  in  adjusting  it  that  the  side  of  the  camera  and 
the  face  of  the  plate-holder,  holding  the  negative,  forms  a  perfect 
right  angle.  If  it  is  desirable  to  make  an  enlarged  transparency, 
say  from  a  4x5  or  5x8  negative  to  an  8x10  plate,  the  same  camera 
and  lens  may  be  used,  but  the  ground  glass  of  the  camera  re- 
moved, allowing  the  magnified  image  to  pass  through  the  camera 
into  the  sensitive  plate,  supported  in  an  upright  position  at  the 
distance  found  to  be  correct ;  to  ascertain  this  the  camera  with 
its  lens  should  slide  easily  between  two  strips,  for,  unless 
your  camera  is  provided  with  a  front  rack  movement,  you  will 
have  to  move  the  camera,  and  with  it  the  lens  to  obtain  a  focus, 
using  a  light  of  glass  on  which  is  stretched  a  piece  of  white  paper 
on  which  to  obtain  a  focus,  and  placed  against  a  support  on  the 
board  carrying  the  camera,  and  at  right  angle  with  the  base  of  it. 
This  is  supposing  you  are  working  in  a  room  in  which  all  light, 
except  that  passing  through  the  negative,  is  excluded  before 
placing  the  negative  in  the  holder  or  support,  if  it  is  desirable  to 
have  a  margin  on  the  transparency  ;  then  cut  out  a  mask  from 
the  thin  red  enameled  paper  or  tin-foil,  and  place  on  the  face  of 
the  negative,  being  careful  to  see  that  the  margin  shows  equally 
around  the  large  plate  or  focusing  screen. 

Now,  while  the  above  description  will  enable  any  one  to  produce 
enlarged  or  reduced  transparencies  from  their  negatives,  it  is  but 
a  makeshift,  and  will  be  found  to  entail  great  loss  of  time  and 


uncertainty  in  working,  all  of  which  can  be  avoided  by  using  a 
properly  constructed  camera,  such  as  that  made  by  the  Scovill 
Manufacturing  Co.*  The  writer  of  this  article  has  had  one  in 
use  for  years.  The  end  holding  the  negative,  has  adjustments 
for  centering  the  image,  and  the  extended  range  of  adjustment  of 
the  lens  enables  a  lantern  transparency  to  be  made  from  an  8x10 
negative,  or  vice  versa,  a  8x10  transparency  from  a  34x44,  or 
other  intermediate  size  negatives. 

Having  explained  the  tools  required,  we  will  now  proceed  with 
describing  the  chemicals  required  and  the  making  of  the  trans- 
parencies. 

Of  chemicals  it  will  require  the  following  : 

Neutral  oxalate  of  potash 1  pound. 

Sulphate  of  iron , 1  pound . 

Hyposulphite  of  soda 5  pounds. 

Alum 1  pound. 

Citric  acid %  pound . 

Liquor  ammonia 4  ounces. 

Plain  collodion  varnish 8  ounces. 

Too  much  stress  cannot  be  laid  in  procuring  chemicals  of  the 
greatest  purity,  and  known  to  be  made  for  use  in  photography  ; 
especially  is  it  necessary  that  the  first  two  articles  named  should 
be  pure.  Many  have  been  disappointed  in  their  efforts  at  trans- 
parency making  by  applying  to  the  country  druggist  for  oxalate 
of  potash,  and  have  been  supplied  with  bin-oxalate  of  potash  ;  be 
careful,  therefore,  to  procure  the  chemicals  from  a  reliable  dealer 
in  photographic  materials.  In  compounding  the  solutions,  first 
prepare,  by  a  thorough  cleansing,  suitable  sized  bottles  ;  for  the 
bulky  solutions,  nothing  is  better  than  the  ordinary  glass  preserve 
jar,  and  for  labels,  a  safe  plan  is  to  cut  from  the  circular  accom- 
panying the  plates  you  are  to  use,  the  formulas,  and  paste  them 
on  the  glass  jar  to  contain  the  solution  it  describes.  Next  in 
importance  is,  the  water,  clear  soft  river  or  spring  water,  melted 
ice  or  distilled  as  most  convenient,  but  not  hard  water  containing 
lime  in  solution. 

We  will  now  describe  a  very  excellent  plan  we  have  used  for 
years  in  dissolving  large  crystals  that  does  away  with  the  use  of 
a  pestal  and  mortar,  and  after  filtering  for  the  A  solution  of  fol- 
lowing formulas,  choose  a  one-half  gallon  glass  preserve  jar,  and 
for  B  solution  a  quart  jar.  Measure  into  each  one  the  quantity  of 
water  required,  except  that  in  the  B  solution  a  few  ounces  of  the 
water  may  be  reserved  until  after  solution  of  the  iron  salt  and 
then  added,  to  dissolve  the  salts  so  as  to  need  no  after  filtering, 

*  Described  minutely  in  Lesson  XIX. 

4 


take  a  common  domestic  salt  bag,  washed  to  free  from  salt,  in 
this  place  the  crystals  and  suspend  it  in  the  water  so  that  the  bulk 
of  the  salt  is  just  covered  by  the  water,  immediately  a  stream  of 
denser  liquid  will  be  seen  falling  to  the  bottom  of  the  jar,  much 
in  appearance  as  when  pouring  glycerine  into  water  ;  this  will 
continue  until  the  whole  of  the  salts  are  dissolved  and  a  clear 
solution,  remove  the  bag,  give  the  bottle  or  jar  a  shake,  and  the 
solution  is  ready  ;  the  same  method  is  to  be  employed  in  dissolv- 
ing the  iron  and  hyposulphite  of  soda,  using  a  separate  bag  for 
each  one,  and  completing  one  before  commencing  on  another. 
Having  everything  ready,  carefully  weigh  out  by  avoirdupois 
weight  the  chemicals,  and  make  solutions  as  per  following 
formula  : 

CARBUTT'S  IMPROVED  DEVELOPER  FOR  TRANSPARENCIES. 

A. — Oxalate  of  potash 8  ounoes. 

Water 30  ounces. 

Citric  acid 60  grains. 

Citrate  of  ammonia  solution 2  ounces. 

B. — Sulphate  of  iron    4  ounces. 

Water 32  ounces. 

Sulphuric  acid 8  drops. 

C. — Citrate  of  Ammonia  Solution. — Dissolve  1  ounce  citric  acid  in  5 
ounces  distilled  water,  add  liquor  ammonia  until  a  slip  of  litmus  paper 
just  loses  the  red  color,  then  add  water  to  make  the  whole  measure  8 
ounces. 

Developer. — Add  1  ounce  of  B  to  2  of  A,  and  J£  ounce  water  and  3  to 
6  drops  bromide  solution. 

In  the  making  of  transparencies,  the  first  requisite  is  a  good 
negative,  and  every  effort  and  care  should  be  taken  when  pro- 
ducing it,  to  insure  its  freedom  from  imperfections  as  possible,  the 
second  requisite  is  a  suitable  artificial  light  for  use  when  making 
exposures  by  contact,  and  we  know  of  none  better  than  Carbutt's 
Multum  in  Parvo  Lantern,  designed  especially  for  this  class  of 
work,  it  has  a  safe  light  in  front,  used  when  developing  negatives 
or  transparencies,  has  two  side  doors,  that  to  the  left  when  opened 
emits  clear  white  light,  and  the  reflector  attached  to  the  revolving 
lamp,  throws  parallel  rays  towards  the  printing  frame  holding  the 
negative  and  sensitive  plate,  the  door  on  the  right,  when  opened 
reveals  a  light  of  opal  glass,  through  which  the  soft  white  light 
allows  the  negative  or  positive  to  be  examined,  the  third  requisite 
is  suitable  sized  developing  dishes;  these  should  be  of  porcelain 
or  the  enameled  iron  ware,  and  can  not  be  used  with  the  pyro  de- 
veloper without  risk  of  staining  the  transparencies,  as  we  use  for 

5 


them  the  ferrous-oxalate  developer  only.  Having  now  provided 
ourselves  with  the  necessary  requisites  for  the  work,  we  will  pro- 
ceed with  the  making  of  transparencies,  beginning  with  the  popu- 
lar lantern  slide;  for  convenience  of  exposing  the  plate  the  lantern 
should  be  hung  in  front  of  the  operator  so  that  the  bottom  is  about 
twelve  inches  from  the  work-bench,  to  the  left  and  in  line  with  the 
bottom  of  lantern  should  be  fixed  a  bracket  shelf,  so  that  the 
printing  frame  can  be  supported  at  a  distance  of  about  twenty 
inches  from  the  lamp  flame.  We  now  place  our  negative  glass 
in  contact  with  the  glass  in  a  deep  printing  frame,  a  suitable  size 
is  6£x8£,  then  it  answers  for  5x8  and  under,  over  this  place  one 
of  Carbutt's  thin  crystal  transparency  plates,  so  as  to  cover  the 
portion  of  the  negative  desired,  lay  a  piece  of  dark  felt  or  other 
soft  material  over  it,  close  down  the  back,  next  turn  the  lamp  of 
the  lantern  by  the  knob  underneath,  so  that  the  reflector  faces  to 
the  left  door  of  the  lantern,  and  allow  the  clear  light  to  act  from 
ten  to  fifteen  seconds,  close  the  door  of  the  lantern,  remove  the 
plate  from  printing  frame,  place  in  a  4£x5£  porcelain  dish,  and  flow 
over  sufficient  of  the  developer  to  well  cover  the  image,  if  cor- 
rectly time  should  appear  slowly,  taking  two  or  three  minutes  to 
complete,  allow  the  development  to  continue  until  the  blacks  look 
quite  strong,  and  detail  plainly  showing  in  the  high  lights,  to  al- 
low for  reduction  of  intensity  in  the  fixing  bath,  wash  off  the  de- 
veloper, and  immerse  in  a  fresh  solution  of  the  hyposulphite  of 
soda,  (pyro  developed  negatives  should  not  be  fixed  in  same  solu- 
tion) made  by  dissolving  8  ounces  of  the  salt  in  40  ounces  of 
water,  in  the  same  manner  as  directed  for  dissolving  the  iron  salt. 
Let  the  transparency  remain  in  the  fixing  bath,  three  to  five 
minutes  after  the  white  bromide  seems  cleared  from  the  plate, 
wash  for  half  an  hour  in  running  water,  then  immerse  for  five 
minutes  in  the 

HARDENING  SOLUTION. 

Water 86  ounces. 

Pulverized  alum Bounces. 

Citric  acid ^4  ounce. 

Afterwards  wash  for  twenty  minutes  to  half  hour,  then  care- 
fully go  over  the  surface  with  a  tuft  of  absorbent  cotten,  while 
water  is  running  over  it,  give  a  final  rinse,  and  place  in  drying 
rack  to  dry  spontaneously,  then  varnish  with  plain  collodion. 

COLLODION  VARNISH. 

Alcohol 4  ounces. 

Pyroxaline 30  to  40  grains. 

Sulphuric  ether 4  ounces. 


When,  after  shaking,  the  cotton  is  dissolved,  filter  and  flow  the 
plain  collodion  over  the  dry  transparency,  the  same  as  when  using 
varnish  ;  then  dry,  cover  with  matt  and  a  crystal  cover  glass,  and 
bind  with  binding  strip. 

Transparencies  for  window  and  door  decoration  should  be  made 
on  plates  somewhat  larger  than  the  negative,  so  that  a  suitable 
margin  may  surround  the  image.  To  do  this,  cut  a  mask  with 
rectangular  or  other  opening  out  of  the  thin  red  enameled  paper ; 
for  an  8x10  transparency  from  a  6ix8£  negative,  take  a  piece  of 
the  mask  paper  9x11  with  two  sides  cut  to  right  angle  ;  make  a 
line  with  pencil  and  ruler  1£  inches  from  two  sides;  from  the  side 
line  measure  5i  inches,  and  from  the  cross  line  measure  7£  inches; 
cut  on  these  lines  with  a  sharp  knife  through  the  paper  laid  on 
glass  or  zinc,  and  remove  the  blank  ;  make  a  x  mark  on  left  upper 
corner,  to  denote  register  corner,  place  this  mask  in  a  10x12  deep 
printing  frame,  let  it  register  close  to  the  left-hand  upper  corner, 
lay  the  negative  film  side  up  and  under  the  mask  ;  adjust  the 
negative  so  as  to  show  in  proper  position  through  the  opening  ; 
over  this  place  a  Carbutt  A  transparency  plate  8x10,  letting  it 
register  in  the  same  corner  as  the  mask  ;  lay  over  a  pad  of  black 
canton  flannel,  close  the  printing  frame,  expose  to  the  lamp  or  gas- 
light 10  to  15  seconds  or  more,  according  to  density  of  negative. 
Develop  as  directed  for  lantern  slides,  and  in  every  other  respect 
proceed  the  same. 

The  tone,  both  of  lantern  and  large  transparencies,  can  be 
varied  from  a  warm  brown  to  a  velvety  black.  Increased  ex- 
posure and  weaker  developer  (adding  water)  with  more  bromide 
gives  warm  brown  tones.  Short  exposure  and  stronger  (undi- 
luted) developer  gives  dark  tones. 


CHAUTAUQUA  UNIVERSITY. 

LEWIS  MILLER,  PRESIDENT. 
J.  H.  VINCENT.  CHANCELLOR.  R.  S.  HOLMES,  REGISTRAR. 


THE 


(Sjauteuqua  {Scjool  of 


SCHOOL    HEADQUARTERS, 

423  BROOME  STREET,  NEW  YORK. 


CHARLES    WAGER     HULL- 
Supt.  of  Instruction,  C.  S.  of  P. 


LESSON  XXII. 

landscape  Photography. 

IT  has  been  said  by  those  engaged  in  the  instruction  of  youth 
that  they  often  find  it  far  more  difficult  to  indicate  from  the 
mind  of  a  pupil  the  errors  of  previous  training  then  it  is  to  impart 
and  render  permanent  such  knowledge  as  is  properly  presented. 
A  false  start  on  the  road  to  knowledge  may  soon  lead  to  dis- 
couragement and  finally  to  overwhelming  disaster.  And  this  is 
especially  liable  with  older  as  well  as  young  students  in  the  tech- 
nical science  and  art  of  photography.  Few,  if  any  student,  in 
any  department  of  art  has  attained  a  prominent  position  in  his  or 
her  profession  without  beginning  with  the  rudiments  and 
thoroughly  mastering  the  first  principles. 

First  lessons  may  seem  uninteresting  and  to  the  beginner  appear 
unnecessary — a  waste  of  time  and  material.  But,  if  neglected, 
it  is  more  than  probable  that  far  more  time  and  greater  expense 
will  be  demanded  for  correction  of  the  mistake,  besides  the  worry 
and  regret  which  is  sure  to  come  with  the  conviction  that  the  be- 
ginning has  been  too  hurried  and  its  details  too  lightly  passed 
over. 

Do  not  expect  to  at  once  produce  results  equal  to  those  of 
workers  who  have  grown  gray  in  the  same  field  of  labor,  and  if 
you  do  have  such  expectations,  do  not  get  discouraged  by  a  few 
failures. 

One  student  in  photography  yet  has  a  vivid  remembrance  of 
his  early  experience  in  the  use  of  a  14x17  outfit  with  which  a 
learned  professor  had  started  him  out  to  make  his  first  pictures. 

It  is  well  to  begin  with  a  fixed  determination  that  quality 
should  be  the  first  and  most  important,  and  quantity  a  secondary 
or  unthought  of  factor.  A  good  picture  of  a  single  tree,  shrub  or 
even  leaf,  a  small  picture  of  a  corner  in  the  garden,  a  field  or  bit 
of  water,  is  far  more  satisfactory,  instructive  and  valuable  than  a 
so-called  fair  picture,  however  broad  the  space  shown  may  be. 
Do  not  try  to  photograph  everything  you  see  ;  select  your  sub- 


ject  after  consideration,  execute  your  work  with  deliberate  care, 
and  you  may  afterward  take  pleasure  in  exhibiting  the  results  to 
your  friends. 

First  secure  good  apparatus.  Do  not  define  the  word  good  as 
here  used  to  necessarily  mean  high  price ;  very  fine  work  is  often 
done  with  comparatively  cheap  tools.  Safety  of  expenditure  is 
best  secured  by  intrusting  orders  to  a  well-known  and  reliable 

firm,  such  as .  Otherwise, 

purchases  of  apparatus  should  be  made  under  the  counsel  or  by 
advice  of  some  competent  person  who  has  been  made  acquainted 
with  the  requirements  and  conditions  of  the  buyer. 

Good,  cheap  apparatus  may  be  found  if  properly  sought  for. 
But  a  great  deal  of  apparatus  is  sold  which  is  dear  at  any  price, 
having  less  real  value  than  the  raw  material  from  which  it  has 
been  constructed. 

After  determining  to  procure  an  outfit,  begin  study  for  its  use. 
Select  subjects  and  study  them  from  various  points  of  view  and 
under  different  lights  of  morning,  noon,  or  later  in  the  day.  Ob- 
serve the  effect  under  various  conditions  of  illumination.  Some 
of  the  finest  photographs  of  American  landscapes  have  been 
made  under  a  clear  or  partially  clouded  sky  just  before  the  morn- 
ing sun  appeared  above  the  horizon.  The  light  reflected  from 
such  a  sky  is  soft  and  yet  brilliant,  while  the  air  usually  has  less 
motion  than  at  any  other  time  of  day,  and  the  dewy  sparkle  of 
the  foliage  is  found  only  in  the  early  hours. 

In  broad  expanse  of  field  and  detached  woodland  the  brighter 
light  of  later  hours  is  often  most  desirable  on  account  of  the  well 
defined  shadows  which  serve  to  break  up  the  monotony  and 
give  brilliancy  to  such  scenes.  A  herd  of  cattle  or  a  flock  of 
sheep — which  add  much  to  the  beauty  of  landscape  pictures — 
are  less  likely  to  be  in  motion,  and  are  oftener  found  in  pictur- 
esque groups  then  in  early  morning.  No  landscape  of  any  con- 
siderable breadth  should  be  photographed  without  the  introduc- 
tion of  animals  or  familiar  figures. 

If  animal  life  is  represented  in  the  picture,  do  not  have  it  in 
the  immediate  foreground,  unless  it  is  to  appear  the  important 
feature  of  the  scene.  Whether  the  figures  used  are  biped  or 
quadruped,  they  should  be  placed  at  such  a  distance  as  will  pre- 
vent their  blocking  out  other  important  objects,  or  giving  the  ap- 
pearance of  crowding.  Many  beautiful  landscape  pictures  may 
be  secured  in  the  late  afternoon  hours,  even  up  to  within  a  short 
time  of  the  sun's  disappearance  below  the  western  horizon.  This 
is  an  especially  favorable  time  of  day  for  fine  cloud  effects.  In 


scenes  made  up  of  large  masses  of  foliage,  it  will  be  found  neces- 
sary to  give  considerably  longer  exposure.  This  increase  of 
exposure  is  very  important  in  heavily  wooded  mountainous 
districts.  The  absorption  of  actinic  force  and  the  low  power  of 
the  reflected  green  rays  are  such,  that  considerable  care  is  neces- 
sary for  producing  fine  work  under  such  conditions. 

Care  should  be  exercised  in  setting  up  the  camera  for  field 
work.  In  most  instances  it  is  advisable  to  place  the  camera  hori- 
zontal and  level,  and  to  make  any  desired  change  in  the  bound- 
aries of  the  picture  by  a  proper  use  of  the  sliding  front  or 
swinging  back  of  the  instrument.  For  more  or  less  sky  or  fore- 
ground, lower  or  elevate  the  sliding  front  or  lens  board  of  the 
box,  and,  for  side  changes,  utilize  the  side  swing  back.  This  last 
named  motion  is  very  important  when  a  long  stretch  of  shore, 
river  or  street  view  is  under  treatment.  By  swinging  the  end  of 
the  ground  glass  focusing  screen,  showing  the1  near  objects  back 
or  further  from  the  lens,  and  the  end  showing  the  distant  objects 
nearer  to  the  lens,  much  finer  rendering  of  details  is  secured. 

When  the  body  of  the  camera  is  much  tipped  up  or  down,  the 
result  is  likely  to  be  greatly  distorted,  and  gives  a  false  character 
to  the  picture  It  is  seldom  advisable  to  photograph  landscape 
scenes  from  the  shadow  side.  The  shadow,  unrelieved  by  illum- 
inated portions,  produces  a  somber  effect  in  the  work. 

The  proper  rendering  of  distant  views  is  best  secured  in  clear, 
bright  weather.  Even  a  slight  veil  of  fog  or  smoke  is  quite  suffi- 
cient to  prevent  good  results,  under  otherwise  most  favorable  con- 
ditions. By  clear  weather,  a  cloudless  sky  is  not  necessarily 
meant,  but  rather  such  conditions  as  show  the  air  to  be  free  from 
smoke  or  fog,  which  give  to  distant  objects  a  dim  or  hazy  appear- 
ance. A  sky  partially  obscured  by  thin,  light,  fleecy  clouds,  re- 
flects an  excellent  light  for  fine  landscape  work.  The  pleasant 
weather  immediately  after  a  heavy  rain  is  very  favorable. 

At  such  times  the  floating  particles  have  been  precipitated  or 
washed  from  the  air,  and  the  dust  with  which  foliage  has  become 
coated  in  dry  weather  no  longer  absorbs  the  light  or  prevents  re- 
flection from  smooth  surfaces. 

When  illustrating  a  scene  including  any  considerable  expanse 
of  water,  choose  some  point  of  view  from  which  the  surface  of 
the  water  does  not  present  a  broad,  brilliant  sheet  of  unbroken 
white.  This  is  sometimes  difficult  if  there  is  neither  a  fresh 
breeze  nor  a  flowing  current ;  and  if  either  of  these  conditions 
exist,  the  picture  is  apt  to  be  unsatisfactory  unless  made  by  in- 
stantaneous exposure,  and  such  short  exposures  often  result 
4 


in  hard  or  inharmonious  prints,  when  considerable  expanse  of 
woodland  or  heavy  foliage  is  included. 

A  field  of  waving  grain  or  the  long  majestic  swing  of  tall  forest 
trees  in  a  heavy  gale  of  wind  are  beautiful  objects  to  look  upon, 
but  are  as  yet  beyond  the  reach  of  photographic  illustration,  be- 
cause the  light,  at  such  times  as  these  scenes  are  presented,  is 
usually  too  weak  for  the  rapid  exposure  required  for  satisfactory 
results  with  moving  objects. 

Beginners,  and  in  fact  old  workers,  are  apt  to  commit  errors  in 
time  of  exposures  in  the  open  air.  This  is  not  mainly  due  from 
lack  of  ability  to  judge  of  the  amount  of  illumination,  but  rather 
to  disregard  of  the  color  of  the  light. 

During  long  periods  of  dry  weather  the  air  becomes  filled  with 
particles  of  floating  matter,  which  gives  the  light  a  yellow  non- 
actinic  tone,  requiring  much  longer  exposures  in  the  camera. 

It  is  advisable  to  keep  full  notes  of  all  work  done  in  the  field, 
as  such  records  often  prove  valuable  in  after  work  of  the  same 
class.  Field  books  for  such  records  may  be  had  from  most  deal- 
ers in  photographic  materials.  Plate  makers  and  chemical  manu- 
facturers are  many  times  blamed  for  faulty  results  which  are  due 
to  lack  of  judgment,  or  its  proper  exercise  when  the  materials  are 
used. 

Greater  care  should  be  used  to  prevent  light  from  reaching  the 
inside  of  the  plate-holder  or  camera  box,  except  such  as  passes 
through  the  lens,  while  the  exposure  is  made.  It  should  be  re- 
membered that  the  light  under  an  open  sky  is  much  stronger 
than  it  is  inside  a  room,  and  a  small  leak  which  would  be  scarce- 
ly noticeable  in  the  latter,  may  be  in  the  former  sufficient  to 
illuminate  the  entire  inside  of  the  camera  box  or  plate-holder. 
A  cloth  or  opaque  cover  is  advisable  for  shading  the  camera  dur- 
ing exposure  in  the  field. 

Some  have  recommended  enveloping  the  entire  camera  box  in  a 
shield  of  some  light  opaque  material  made  up  in  the  form  of  a  bag 
sufficiently  large  to  admit  of  drawing  and  replacing  the  slide  with- 
out removing  or  opening  the  box. 

Every  record  of  field  work  should  state  the  focus  of  the  lens 
used  and  the  exact  diameter  of  the  stop  or  diaphragm.  To  state 

that  you  used  for  certain  results  Mr.  S 's  lens  with  number  3 

stop  really  conveys  no  information  to  the  listener  unless  he  is 

familiar  with  these.  But  when  you  say  I  used  Mr.  S 's  8-inch 

focus  lens  with  £-inch  diaphragm,  your  listener  can  at  once  under- 
stand the  conditions  under  which  the  picture  described  was 
made. 


The  development  of  a  landscape  plate  should  theoretically  not 
be  different  from  that  of  other  work,  but  when  we  consider  the 
variety  of  influences  bearing  upon  the  work,  among  which  are 
principally  the  varying  conditions  of  light,  it  will  readily  be  un- 
derstood that  a  different  procedure  must  be  adopted. 

It  may  be  taken  as  a  rule,  that  for  timed  landscape  work  no  bet- 
ter plate  can  be  found  in  the  American  market  than  our  favorite, 
the  Carbutt  B,  with  which  we  have  become  familiar,  and  the  fine 
qualities  of  which  we  have  had  ample  opportunity  to  observe. 
Time  of  exposure  depends  in  landscape  photography,  as  well  as  in 
any  other  branch  :,f  the  art,  first  upon  the  degree  of  sensitiveness  of 
the  plate,  the  c,uality  of  light,  the  time  of  day,  and  the  color  of  the 
object.  So,  for  instance,  will  dark  green  wooded  scenery  require  a 
much  longer  time  than  a  view  on  the  lake  shore  or  ocean  beach  ; 
a  white  marble  palace  or  a  white  frame  cottage  much  less  than  a 
brick  or  brown-stone-front  house. 

The  results  of  the  practicing  class,  1886,  of  C.  S.  P.,  encourage 
us  to  continue,  for  that  class  of  work,  with  the  Chautauqua  de- 
veloper. 

A. — Bromide  of  ammonium 2  drams. 

Water 8  ounces. 

B. — Aqua  ammonia 1  ounce. 

Water 7  ounces. 

C. — Pyrogallic  acid 1  dram. 

Water 12  ounces. 

Nitric  acid.  .  .    5  minims. 

For  properly  timed  exposures  take  of 

A 40  minims. 

B 20  minims. 

C 1^  ounce. 

Water 2  ounces. 

For  over-exposures  restrain  the  action  by  adding  to  each  ounce 
of  the  mixed  developer  from  3  to  5  minims  of  A,  and  for  under- 
exposures accelerate  with  a  few  drops  of  B,  being  careful  not  to 
use  it  excessively,  for  then  green  fog  will  invariably  result. 

For  instantaneous  exposures,  when  but  rarely  the  proper  time 
can  be  approximately  estimated,  the  mode  of  operating  requires  a 
variety  of  modification. 

We  return  here  to  the  original  developer  as  described  in  Les- 
son No.  VI. 

When,  on  account  of  weak  light  or  extremely  rapid  speed 
6 


of  the  shutter,  under-exposure  may  be  reasonably  suspected,  a 
good  method  is  to  bathe  the  plate  in  a  diluted  alkali  solution  be- 
fore proceeding  with  the  development. 

The  alkali  solution  No.  2,  of  Lesson  No.  VI,  may  be  mixed  with 
three  volumes  of  water.  After  the  plate  has  soaked  in  this  for 
two  or  three  minutes,  it  is  removed,  washed,  and  placed  in  diluted 
developer  of  the  normal  composition.  The  strength  of  the  devel- 
oper may  be  increased  as  the  process  goes  on,  until  a  proper 
amount  of  detail  and  density  is  obtained. 

In  our  opinion  the  finest  results  can  be  effected  by  merely 
modifying  the  developer.  When  a  plate  shows  signs  of  under- 
exposure, the  normal  developer  must  be  at  once  removed  and  a 
quantity  of  pure  water  poured  into  the  tray  in  which  the  plate  re- 
mains while  the  operator  is  mixing  a  new  developer  to  suit  the 
peculiar  case. 

All  authorities  and  the  most  successful  practitioners  advise  the 
employment  of  a  weak  developer  in  cases  of  under-exposure,  at 
the  commencement  of  the  operation.  Often  it  becomes  necessary 
to  change  the  developer  several  times  in  the  course  of  one  devel- 
opment, each  solution  being  prepared  to  suit  the  exact  state  of 
the  plate  in  which  the  previous  one  left  it.  Old  developers,  that 
is,  those  which  have  been  used  once  or  twice,  are  very  serviceable 
for  starting  the  action  on  an  undertimed  plate. 

As  the  process  progresses,  it  will  be  seen  what  treatment  is 
necessary,  and  a  fresh  developer,  which  is  rather  weak  in  alkali, 
perhaps,  will  be  used  in  place  of  the  old  one.  A  weak  developer, 
if  used  to  the  end,  will  yield  but  a  feeble  negative ;  it  must  be 
strengthened  as  the  development  continues.  Of  course,  it  re- 
quires a  much  longer  time  to  complete  development  when  a  weak 
developer  is  employed  and  the  process  is  stopped  from  time  to 
time  to  prepare  new  and  slightly  stronger  solutions  ;  but  the  re- 
sult is  reasonably  sure.  With  the  proper  amount  of  time  and 
patience,  a  fair  printing  negative  can  be  produced  by  this  method 
of  procedure  from  a  plate  that  was  apparently  under-exposed. 

Never  force  an  under-timed  negative  by  increasing  the  amount 
of  alkali  in  the  developer  ;  it  can  only  result  in  failure.  A  devel- 
oper which  is  very  strong  in  soda  or  potash  frequently  causes  a 
plate  to  frili,  besides  yielding  a  hard  and  glassy -negative.  If  too 
much  ammonia  is  used,  the  result  is  green  fog.  Forcing  an  un- 
der-timed plate  almost  invariably  results  in  a  foggy  negative. 
The  temperature,  too,  is  an  important  condition  to  be  observed 
when  preparing  a  developer.  In  summer  and  varm  weather  con- 
siderably less  alkali  is  needed  than  in  colder  weather. 
7 


When  over-exposures  may  be  reasonably  suspected,  which 
quite  frequently  occurs  with  highly  sensitive  plates  and  in  good 
conditions  of  light,  the  above  method  may  be  reversed,  and  devel- 
opment commenced  with  a  diluted  solution  of  pyrogallic  acid, 
No.  1,  Lesson  No.  VI.  Alkaline  solution  is  then  added  as  the  plate 
demands,  and  the  proportions  of  pyro  increased  accordingly. 

The  drop-shutter — an  indispensable  instrument  for  instantane- 
ous exposures — explains  itself  by  the  simple  mode  of  construc- 
tion and  easy  way  of  attachment. 


DUPLEX.  SCOVILL'S 

UNIVERSAL  SAFETY  SHUTTER. 

A    more    complicated    arrangement    is  found    in    the   Prosch 
Duplex." 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 

Los  Angeles 
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